1
|
Li WM, Zhao JF, Cao LP, Hu Z, Huang QZ, Wang XC, Liu Y, Zhao GQ, Zhang J, Liu QQ, Yu RZ, Long YW, Wu H, Lin HJ, Chen CT, Li Z, Gong ZZ, Guguchia Z, Kim JS, Stewart GR, Uemura YJ, Uchida S, Jin CQ. Superconductivity in a unique type of copper oxide. Proc Natl Acad Sci U S A 2019; 116:12156-12160. [PMID: 31109998 PMCID: PMC6589659 DOI: 10.1073/pnas.1900908116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics. High-T c cuprates crystallize into a layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn Teller effect in combination with the strong static Coulomb interaction, the octahedra in high-T c cuprates are elongated along the c axis, leading to a 3dx 2-y 2 orbital at the top of the band structure wherein the doped holes reside. This scenario gives rise to 2D characteristics in high-T c cuprates that favor d-wave pairing symmetry. Here, we report superconductivity in a cuprate Ba2CuO4-y , wherein the local octahedron is in a very exceptional compressed version. The Ba2CuO4-y compound was synthesized at high pressure at high temperatures and shows bulk superconductivity with critical temperature (T c ) above 70 K at ambient conditions. This superconducting transition temperature is more than 30 K higher than the T c for the isostructural counterparts based on classical La2CuO4 X-ray absorption measurements indicate the heavily doped nature of the Ba2CuO4-y superconductor. In compressed octahedron, the 3d3z 2-r 2 orbital will be lifted above the 3dx 2-y 2 orbital, leading to significant 3D nature in addition to the conventional 3dx 2-y 2 orbital. This work sheds important light on advancing our comprehensive understanding of the superconducting mechanism of high T c in cuprate materials.
Collapse
Affiliation(s)
- W M Li
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
- Materials Research Lab at Songshan Lake, 523808 Dongguan, China
| | - J F Zhao
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - L P Cao
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - Z Hu
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, 01187 Dresden, Germany
| | - Q Z Huang
- NIST Center for Neutron Research, Gaithersburg, MD 20899
| | - X C Wang
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
- Materials Research Lab at Songshan Lake, 523808 Dongguan, China
| | - Y Liu
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - G Q Zhao
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - J Zhang
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - Q Q Liu
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
| | - R Z Yu
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
- Materials Research Lab at Songshan Lake, 523808 Dongguan, China
| | - Y W Long
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
- Materials Research Lab at Songshan Lake, 523808 Dongguan, China
| | - H Wu
- NIST Center for Neutron Research, Gaithersburg, MD 20899
| | - H J Lin
- National Synchrotron Radiation Research Center, 30076 Hsinchu, Taiwan
| | - C T Chen
- National Synchrotron Radiation Research Center, 30076 Hsinchu, Taiwan
| | - Z Li
- School of Materials Science and Engineering, Nanjing University of Science and Technology, 210094 Nanjing, China
| | - Z Z Gong
- Department of Physics, Columbia University, New York, NY 10027
| | - Z Guguchia
- Department of Physics, Columbia University, New York, NY 10027
| | - J S Kim
- Department of Physics, University of Florida, Gainesville, FL 32611
| | - G R Stewart
- Department of Physics, University of Florida, Gainesville, FL 32611
| | - Y J Uemura
- Department of Physics, Columbia University, New York, NY 10027
| | - S Uchida
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- Department of Physics, University of Tokyo, 113-0033 Tokyo, Japan
| | - C Q Jin
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China;
- School of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190 Beijing, China
- Materials Research Lab at Songshan Lake, 523808 Dongguan, China
| |
Collapse
|
2
|
Han W, Chen BJ, Gu B, Zhao GQ, Yu S, Wang XC, Liu QQ, Deng Z, Li WM, Zhao JF, Cao LP, Peng Y, Shen X, Zhu XH, Yu RC, Maekawa S, Uemura YJ, Jin CQ. Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin & charge doping. Sci Rep 2019; 9:7490. [PMID: 31097727 PMCID: PMC6522530 DOI: 10.1038/s41598-019-43754-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 12/13/2018] [Indexed: 11/09/2022] Open
Abstract
We report a new diluted ferromagnetic semiconductor Li1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn2+ into Cd2+. The extended Cd 4d-orbitals lead to more itinerant characters of Li1+y(Cd,Mn)P than that of analogous Li1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li1+y(Zn,Mn)P is obtained in Li1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p-type carriers are determined by Hall effect measurements. The first principle calculations and X-ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li1+y(Cd,Mn)P shows a very low coercive field (<100 Oe) and giant negative magnetoresistance (~80%) in ferromagnetic state that will benefit potential spintronics applications.
Collapse
Affiliation(s)
- W Han
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China.,Department of Physics and Electronic Engineering, Hebei Normal University for Nationalities, Chengde, 067000, China
| | - B J Chen
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - B Gu
- Kavli Institute for Theoretical Sciences & CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China.,Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan
| | - G Q Zhao
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - S Yu
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - X C Wang
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Q Q Liu
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Z Deng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. .,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China.
| | - W M Li
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - J F Zhao
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - L P Cao
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Y Peng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,Department of Materials Science & Engineering, Sichuan University, Chengdu, China
| | - X Shen
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - X H Zhu
- Department of Materials Science & Engineering, Sichuan University, Chengdu, China
| | - R C Yu
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - S Maekawa
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan
| | - Y J Uemura
- Department of Physics, Columbia University, New York, New York, 10027, USA
| | - C Q Jin
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. .,School of Physics, University of Chinese Academy of Sciences, Beijing, 100190, China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
| |
Collapse
|
3
|
Wang CG, Li Z, Yang J, Xing LY, Dai GY, Wang XC, Jin CQ, Zhou R, Zheng GQ. Electron Mass Enhancement near a Nematic Quantum Critical Point in NaFe_{1-x}Co_{x}As. Phys Rev Lett 2018; 121:167004. [PMID: 30387623 DOI: 10.1103/physrevlett.121.167004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/05/2018] [Indexed: 06/08/2023]
Abstract
A magnetic order can be completely suppressed at zero temperature (T), by doping carriers or applying pressure, at a quantum critical point, around which physical properties change drastically. However, the situation is unclear for an electronic nematic order that breaks rotation symmetry. Here, we report nuclear magnetic resonance studies on NaFe_{1-x}Co_{x}As where magnetic and nematic transitions are well separated. The nuclear magnetic resonance spectrum is sensitive to inhomogeneous magnetic fields in the vortex state, which is related to London penetration depth λ_{L} that measures the electron mass m^{*}. We discovered two peaks in the doping dependence of λ_{L}^{2}(T∼0), one at x_{M}=0.027 where the spin-lattice relaxation rate shows quantum critical behavior, and another at x_{c}=0.032 around which the nematic transition temperature extrapolates to zero and the electrical resistivity shows a T-linear variation. Our results indicate that a nematic quantum critical point lies beneath the superconducting dome at x_{c} where m^{*} is enhanced. The impact of the nematic fluctuations on superconductivity is discussed.
Collapse
Affiliation(s)
- C G Wang
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Z Li
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - J Yang
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
| | - L Y Xing
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
| | - G Y Dai
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - X C Wang
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
| | - C Q Jin
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - R Zhou
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
| | - Guo-Qing Zheng
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Department of Physics, Okayama University, Okayama 700-8530, Japan
| |
Collapse
|
4
|
Zhao GQ, Li Z, Sun F, Yuan Z, Chen BJ, Yu S, Peng Y, Deng Z, Wang XC, Jin CQ. Effects of high pressure on the ferromagnetism and in-plane electrical transport of (Ba 0.904K 0.096)(Zn 0.805Mn 0.195) 2As 2 single crystal. J Phys Condens Matter 2018; 30:254001. [PMID: 29741494 DOI: 10.1088/1361-648x/aac367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Pressure technique is an effective way to modify magnetic properties of diluted magnetic semiconductors (DMS). Based on single crystal, in-plane electrical transport properties of a new generation DMS (Ba0.904K0.096)(Zn0.805Mn0.195)2As2 have been measured with hydrostatic pressure up to 1.8 GPa. Magnetic properties of the single crystal sample are effectively tuned by pressure. Upon compression, the in-plane resistivity initially decreases but then increases when pressure is higher than 1.2 GPa. First principle calculations suggest that decrease of the resistivity is due to enhancement of density of state at Femi energy while increase of the resistivity under higher pressure is caused by distorted MnAs4 tetrahedra. We reveal that the configuration of the MnAs4 tetrahedra and strength of interlayer As-As bonding are of importance to ferromagnetic coupling of (Ba,K)(Zn,Mn)2As2.
Collapse
Affiliation(s)
- G Q Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China. School of Physics, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Zhao JY, Bi W, Sinogeikin S, Hu MY, Alp EE, Wang XC, Jin CQ, Lin JF. A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature. Rev Sci Instrum 2017; 88:125109. [PMID: 29289218 DOI: 10.1063/1.4999787] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new miniature panoramic diamond anvil cell (mini-pDAC) as well as a unique gas membrane-driven mechanism is developed and implemented to measure electronic, magnetic, vibrational, and thermodynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the synchrotron Mössbauer spectroscopy (SMS) simultaneously at high pressure (over Mbar) and low temperature (T < 10 K). The gas membrane system allows in situ pressure tuning of the mini-pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat system to achieve low temperatures, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The system has achieved sample temperatures as low as 9 K. Using the membrane, sample pressures of up to 1.4 Mbar have been generated from this mini-pDAC. The instrument has been routinely used at 3-ID, Advanced Photon Source, for NRIXS and SMS studies. The same instrument can easily be used for other X-ray techniques, such as X-ray radial diffraction, X-ray Raman scattering, X-ray emission spectroscopy, and X-ray inelastic scattering under high pressure and low temperature. In this paper, technical details of the mini-pDAC, membrane engaging mechanism, and the cryostat system are described, and some experimental results are discussed.
Collapse
Affiliation(s)
- J Y Zhao
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - W Bi
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - S Sinogeikin
- High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA
| | - M Y Hu
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - E E Alp
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - X C Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 10090, People's Republic of China
| | - C Q Jin
- Institute of Physics, Chinese Academy of Sciences, Beijing 10090, People's Republic of China
| | - J F Lin
- Department of Geology Sciences, The University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
6
|
Zhao GQ, Lin CJ, Deng Z, Gu GX, Yu S, Wang XC, Gong ZZ, Uemura YJ, Li YQ, Jin CQ. Single Crystal Growth and Spin Polarization Measurements of Diluted Magnetic Semiconductor (BaK)(ZnMn) 2As 2. Sci Rep 2017; 7:14473. [PMID: 29101360 PMCID: PMC5670247 DOI: 10.1038/s41598-017-08394-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 07/12/2017] [Indexed: 11/09/2022] Open
Abstract
Recently a new diluted magnetic semiconductor, (Ba,K)(Zn,Mn)2As2 (BZA), with high Curie temperature was discovered, showing an independent spin and charge-doping mechanism. This makes BZA a promising material for spintronics devices. We report the successful growth of a BZA single crystal for the first time in this study. An Andreev reflection junction, which can be used to evaluate spin polarization, was fabricated based on the BZA single crystal. A 66% spin polarization of the BZA single crystal was obtained by Andreev reflection spectroscopy analysis.
Collapse
Affiliation(s)
- G Q Zhao
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100190, China
| | - C J Lin
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
| | - Z Deng
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
| | - G X Gu
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
| | - S Yu
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
| | - X C Wang
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China
| | - Z Z Gong
- Department of Physics, Columbia University, New York, NY, 10027, USA
| | - Yasutomo J Uemura
- Department of Physics, Columbia University, New York, NY, 10027, USA
| | - Y Q Li
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100190, China.
| | - C Q Jin
- Institute of Physics, Chinese Academy of Sciences; Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100190, China.
| |
Collapse
|
7
|
Liu Y, Long YJ, Zhao LX, Nie SM, Zhang SJ, Weng YX, Jin ML, Li WM, Liu QQ, Long YW, Yu RC, Gu CZ, Sun F, Yang WG, Mao HK, Feng XL, Li Q, Zheng WT, Weng HM, Dai X, Fang Z, Chen GF, Jin CQ. Superconductivity in HfTe 5 across weak to strong topological insulator transition induced via pressures. Sci Rep 2017; 7:44367. [PMID: 28300156 PMCID: PMC5353664 DOI: 10.1038/srep44367] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/07/2017] [Indexed: 11/17/2022] Open
Abstract
Recently, theoretical studies show that layered HfTe5 is at the boundary of weak & strong topological insulator (TI) and might crossover to a Dirac semimetal state by changing lattice parameters. The topological properties of 3D stacked HfTe5 are expected hence to be sensitive to pressures tuning. Here, we report pressure induced phase evolution in both electronic & crystal structures for HfTe5 with a culmination of pressure induced superconductivity. Our experiments indicated that the temperature for anomaly resistance peak (Tp) due to Lifshitz transition decreases first before climbs up to a maximum with pressure while the Tp minimum corresponds to the transition from a weak TI to strong TI. The HfTe5 crystal becomes superconductive above ~5.5 GPa where the Tp reaches maximum. The highest superconducting transition temperature (Tc) around 5 K was achieved at 20 GPa. Crystal structure studies indicate that HfTe5 transforms from a Cmcm phase across a monoclinic C2/m phase then to a P-1 phase with increasing pressure. Based on transport, structure studies a comprehensive phase diagram of HfTe5 is constructed as function of pressure. The work provides valuable experimental insights into the evolution on how to proceed from a weak TI precursor across a strong TI to superconductors.
Collapse
Affiliation(s)
- Y Liu
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Y J Long
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - L X Zhao
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - S M Nie
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - S J Zhang
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Y X Weng
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - M L Jin
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - W M Li
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Q Q Liu
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Y W Long
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - R C Yu
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - C Z Gu
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - F Sun
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - W G Yang
- Center for High Pressure Science &Technology Advanced Research, Shanghai, 201203, China
| | - H K Mao
- Center for High Pressure Science &Technology Advanced Research, Shanghai, 201203, China
| | - X L Feng
- Department of Materials Science, Jilin University, Changchun 130012, China
| | - Q Li
- Department of Materials Science, Jilin University, Changchun 130012, China
| | - W T Zheng
- Department of Materials Science, Jilin University, Changchun 130012, China
| | - H M Weng
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - X Dai
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Z Fang
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - G F Chen
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - C Q Jin
- Institute of Physics &School of Physics of University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| |
Collapse
|
8
|
Xing LY, Miao H, Wang XC, Ma J, Liu QQ, Deng Z, Ding H, Jin CQ. The anomaly Cu doping effects on LiFeAs superconductors. J Phys Condens Matter 2014; 26:435703. [PMID: 25299428 DOI: 10.1088/0953-8984/26/43/435703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The Cu substitution effect on the superconductivity of LiFeAs has been studied in comparison with Co/Ni substitution. It is found that the shrinking rate of the lattice parameter c for Cu substitution is much smaller than that of Co/Ni substitution. This is in conjugation with the observation of ARPES that shows almost the same electron and hole Fermi surfaces (FSs) size for undoped and Cu substituted LiFeAs sample, except for a very small hole band sinking below Fermi level with doping. This indicates that there is little doping effect at Fermi surface by Cu substitution, in sharp contrast to the more effective carrier doping effect by Ni or Co.
Collapse
Affiliation(s)
- L Y Xing
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Zhu J, Zhang JL, Kong PP, Zhang SJ, Yu XH, Zhu JL, Liu QQ, Li X, Yu RC, Ahuja R, Yang WG, Shen GY, Mao HK, Weng HM, Dai X, Fang Z, Zhao YS, Jin CQ. Superconductivity in topological insulator Sb2Te3 induced by pressure. Sci Rep 2014; 3:2016. [PMID: 23783511 PMCID: PMC3687246 DOI: 10.1038/srep02016] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 05/17/2013] [Indexed: 11/09/2022] Open
Abstract
Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. Superconductivity was previously realized in a Cu-intercalated Bi2Se3 topological compound or a Bi2Te3 topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb2Te3 when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb2Te3 retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.
Collapse
Affiliation(s)
- J Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Zhao Z, Wang S, Qi TF, Zeng Q, Hirai S, Kong PP, Li L, Park C, Yuan SJ, Jin CQ, Cao G, Mao WL. Pressure induced second-order structural transition in Sr₃Ir₂O₇. J Phys Condens Matter 2014; 26:215402. [PMID: 24805299 DOI: 10.1088/0953-8984/26/21/215402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We conducted in situ angle dispersive high pressure x-ray diffraction experiments on Sr3Ir2O7 up to 23.1 GPa at 25 K with neon as the pressure transmitting medium. Pressure induces a highly anisotropic compressional behavior seen where the tetragonal plane is compressed much faster than the perpendicular direction. By analyzing different aspects of the diffraction data, a second-order structural transition is observed at approximately 14 GPa, which is accompanied by the insulating state to nearly metallic state at 13.2 GPa observed previously (Li et al 2013 Phys. Rev. B 87 235127). Our results highlight the coupling between electronic state and lattice structure in Sr3Ir2O7 under pressure.
Collapse
Affiliation(s)
- Z Zhao
- Department of Physics, Stanford University, Stanford, CA 94305, USA. Photon Science and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Wu JJ, Lin JF, Wang XC, Liu QQ, Zhu JL, Xiao YM, Chow P, Jin CQ. Magnetic and structural transitions of SrFe2As2 at high pressure and low temperature. Sci Rep 2014; 4:3685. [PMID: 24418845 PMCID: PMC3890939 DOI: 10.1038/srep03685] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/04/2013] [Indexed: 12/02/2022] Open
Abstract
One of key issues in studying iron based superconductors is to understand how the magnetic phase of the parent compounds evolves. Here we report the systematic investigation of paramagnetic to antiferromagnetic and tetragonal to orthorhombic structural transitions of “122” SrFe2As2 parent compound using combined high resolution synchrotron Mössbauer spectroscopy and x-ray diffraction techniques in a cryogenically cooled high pressure diamond anvil cell. It is found that although the two transitions are coupled at 205 K at ambient pressure, they are concurrently suppressed to much lower temperatures near a quantum critical pressure of approximately 4.8 GPa where the antiferromagnetic state transforms into bulk superconducting state. Our results indicate that the lattice distortions and magnetism jointly play a critical role in inducing superconductivity in iron based compounds.
Collapse
Affiliation(s)
- J J Wu
- 1] Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, TX 78712, USA
| | - J F Lin
- Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, TX 78712, USA
| | - X C Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Q Q Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J L Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Y M Xiao
- HPCAT, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - P Chow
- HPCAT, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - C Q Jin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
12
|
Kong PP, Zhang JL, Zhang SJ, Zhu J, Liu QQ, Yu RC, Fang Z, Jin CQ, Yang WG, Yu XH, Zhu JL, Zhao YS. Superconductivity of the topological insulator Bi2Se3 at high pressure. J Phys Condens Matter 2013; 25:362204. [PMID: 23945091 DOI: 10.1088/0953-8984/25/36/362204] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The pressure-induced superconductivity and structural evolution of Bi2Se3 single crystals are studied. The emergence of superconductivity at an onset transition temperature (Tc) of about 4.4 K is observed at around 12 GPa. Tc increases rapidly to a maximum of 8.2 K at 17.2 GPa, decreases to around 6.5 K at 23 GPa, and then remains almost constant with further increases in pressure. Variations in Tc with respect to pressure are closely related to the carrier density, which increases by over two orders of magnitude from 2 to 23 GPa. High-pressure synchrotron radiation measurements reveal structural transitions at around 12, 20, and above 29 GPa. A phase diagram of superconductivity versus pressure is also constructed.
Collapse
Affiliation(s)
- P P Kong
- Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kim JS, Stewart GR, Xing LY, Wang XC, Jin CQ. Specific heat versus field for LiFe(1-x)Cu(x)As. J Phys Condens Matter 2012; 24:475701. [PMID: 23103601 DOI: 10.1088/0953-8984/24/47/475701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
LiFeAs is one of the new class of iron superconductors with a bulk [Formula: see text] in the 15-17 K range. We report on the specific heat characterization of single crystal material prepared by self-flux growth techniques with significantly improved properties, including a much decreased residual gamma, γ(r) (≡C/T as T → 0), in the superconducting state. Thus, in contrast to previous explanations of a finite γ(r) in LiFeAs being due to intrinsic states in the superconducting gap, the present work shows that such a finite residual γ in LiFeAs is instead a function of sample quality. Further, since LiFeAs has been characterized as nodeless with multiple superconducting gaps, we report here on its specific heat properties in zero and applied magnetic fields, to compare to similar results on nodal iron superconductors. For comparison, we also investigate LiFe(0.98)Cu(0.02)As, which has the reduced T(c) of ≈9 K and an H(c2) of 15 T. Interestingly, although presumably both LiFeAs and LiFe(0.98)Cu(0.02)As are nodeless, they clearly show a non-linear dependence of the electronic density of states (is proportional to specific heat γ) at the Fermi energy in the mixed state with the applied field, similar to the Volovik effect for nodal superconductors. However, rather than indicating nodal behavior, the satisfactory comparison with a recent theory for γ(H) for a superconductor with two isotropic gaps in the presence of impurities argues for nodeless behavior. Thus, in terms of specific heat in a magnetic field, LiFeAs can serve as the prototypical multiband, nodeless iron superconductor.
Collapse
Affiliation(s)
- J S Kim
- Department of Physics, University of Florida, Gainesville, FL 32611-8440, USA
| | | | | | | | | |
Collapse
|
14
|
Haskel D, Fabbris G, Zhernenkov M, Kong PP, Jin CQ, Cao G, van Veenendaal M. Pressure tuning of the spin-orbit coupled ground state in Sr2IrO4. Phys Rev Lett 2012; 109:027204. [PMID: 23030204 DOI: 10.1103/physrevlett.109.027204] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Indexed: 06/01/2023]
Abstract
X-ray absorption spectroscopy studies of the magnetic-insulating ground state of Sr2IrO4 at ambient pressure show a clear deviation from a strong spin-orbit (SO) limit J(eff)=1/2 state, a result of local exchange interactions and a nonzero tetragonal crystal field mixing SO split J(eff)=1/2, 3/2 states. X-ray magnetic circular dichroism measurements in a diamond anvil cell show a magnetic transition at a pressure of ∼17 GPa, where the "weak" ferromagnetic moment is quenched despite transport measurements showing insulating behavior to at least 40 GPa. The magnetic transition has implications for the origin of the insulating gap and the nature of exchange interactions in this SO coupled system. The expectation value of the angular part of the SO interaction, <L·S>, extrapolates to zero at ∼80-90 GPa where an increased bandwidth strongly mixes J(eff)=1/2, 3/2 states and SO interactions no longer dominate the electronic ground state of Sr2IrO4.
Collapse
Affiliation(s)
- D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Cheng JG, Zhou JS, Goodenough JB, Zhou HD, Matsubayashi K, Uwatoko Y, Kong PP, Jin CQ, Yang WG, Shen GY. Pressure effect on the structural transition and suppression of the high-spin state in the triple-layer T'-La4Ni3O8. Phys Rev Lett 2012; 108:236403. [PMID: 23003979 DOI: 10.1103/physrevlett.108.236403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Indexed: 06/01/2023]
Abstract
We report a comprehensive high-pressure study on the triple-layer T'-La4Ni3O8 with a suite of experimental probes, including structure determination, magnetic, and transport properties up to 50 GPa. Consistent with a recent ab inito calculation, application of hydrostatic pressure suppresses an insulator-metal spin-state transition at P(c)≈6 GPa. However, a low-spin metallic phase does not emerge after the high-spin state is suppressed to the lowest temperature. For P>20 GPa, the ambient T' structure transforms gradually to a T(†)-type structure, which involves a structural reconstruction from fluorite La-O2-La blocks under low pressures to rock-salt LaO-LaO blocks under high pressures. Absence of the metallic phase under pressure has been discussed in terms of local displacements of O2- ions in the fluorite block under pressure before a global T(†) phase is established.
Collapse
Affiliation(s)
- J-G Cheng
- Materials Science and Engineering Program/Mechanical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Zhang JL, Zhang SJ, Weng HM, Zhang W, Yang LX, Liu QQ, Feng SM, Wang XC, Yu RC, Cao LZ, Wang L, Yang WG, Liu HZ, Zhao WY, Zhang SC, Dai X, Fang Z, Jin CQ. Pressure-induced superconductivity in topological parent compound Bi2Te3. Proc Natl Acad Sci U S A 2011; 108:24-8. [PMID: 21173267 PMCID: PMC3017179 DOI: 10.1073/pnas.1019040108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024] Open
Abstract
We report a successful observation of pressure-induced superconductivity in a topological compound Bi(2)Te(3) with T(c) of ∼3 K between 3 to 6 GPa. The combined high-pressure structure investigations with synchrotron radiation indicated that the superconductivity occurred at the ambient phase without crystal structure phase transition. The Hall effects measurements indicated the hole-type carrier in the pressure-induced superconducting Bi(2)Te(3) single crystal. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi(2)Te(3) due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.
Collapse
Affiliation(s)
- J. L. Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Department of Physics, University of Science and Technology of China, Hefei 230026, China
| | - S. J. Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - H. M. Weng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - W. Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - L. X. Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Q. Q. Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - S. M. Feng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - X. C. Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - R. C. Yu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - L. Z. Cao
- Department of Physics, University of Science and Technology of China, Hefei 230026, China
| | - L. Wang
- HPsync, Geophysical Laboratory, Carnegie Institution of Washington, Advanced Photon Source, Argonne, IL 60439
| | - W. G. Yang
- HPsync, Geophysical Laboratory, Carnegie Institution of Washington, Advanced Photon Source, Argonne, IL 60439
| | - H. Z. Liu
- Natural Science Research Center, Harbin Institute of Technology, Harbin 150080, China
| | - W. Y. Zhao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - S. C. Zhang
- Department of Physics, McCullough Building, Stanford University, Stanford, CA 94305-4045; and
- Center for Advanced Study, Tsinghua University, Beijing 100084, China
| | - X. Dai
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Z. Fang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - C. Q. Jin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
17
|
Zhao K, Liu QQ, Wang XC, Deng Z, Lv YX, Zhu JL, Li FY, Jin CQ. Superconductivity above 33 K in (Ca(₁ - x)Na(x))Fe₂As₂. J Phys Condens Matter 2010; 22:222203. [PMID: 21393737 DOI: 10.1088/0953-8984/22/22/222203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report the synthesis of (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ showing a superconducting transition with T(c) above 33 K. Both dc magnetic susceptibility or specific heat measurements indicated the bulk superconductivity nature of the sample. We also have successfully grown single crystals of the (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ superconductors. The single crystals exhibit sharp superconducting transitions with T(c) above 33 K. The effects of magnetic field on the superconducting transitions are studied, giving rise to high upper critical fields with H(c₂)(c)≈85 T and H(c₂)(ab)≈172 T, respectively. The anisotropy parameter was calculated to be around 2.
Collapse
Affiliation(s)
- K Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Yan XQ, Tang Z, Zhang L, Guo JJ, Jin CQ, Zhang Y, Goto T, McCauley JW, Chen MW. Depressurization amorphization of single-crystal boron carbide. Phys Rev Lett 2009; 102:075505. [PMID: 19257688 DOI: 10.1103/physrevlett.102.075505] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Indexed: 05/27/2023]
Abstract
We report depressurization amorphization of single-crystal boron carbide (B4C) investigated by in situ high-pressure Raman spectroscopy. It was found that localized amorphization of B4C takes place during unloading from high pressures, and nonhydrostatic stresses play a critical role in the high-pressure phase transition. First-principles molecular dynamics simulations reveal that the depressurization amorphization results from pressure-induced irreversible bending of C-B-C atomic chains cross-linking 12 atom icosahedra at the rhombohedral vertices.
Collapse
Affiliation(s)
- X Q Yan
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Yao LD, Li FY, Li JX, Jin CQ, Yu RC. Study of the products of melamine (C3N6H6) treated at high pressure and high temperature. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/pssa.200421177] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
20
|
Yang HD, Lin JY, Li HH, Hsu FH, Liu CJ, Li SC, Yu RC, Jin CQ. Order parameter of MgB(2): a fully gapped superconductor. Phys Rev Lett 2001; 87:167003. [PMID: 11690227 DOI: 10.1103/physrevlett.87.167003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2001] [Indexed: 05/23/2023]
Abstract
We have measured the low-temperature specific heat C(T) for polycrystalline MgB(2) prepared by high pressure synthesis. C(T) below 10 K vanishes exponentially, which unambiguously indicates a fully opened superconducting energy gap. However, this gap is found to be too small to account for T(c) of MgB(2). Together with the small specific heat jump Delta C/gamma(n)T(c) = 1.09, scenarios such as anisotropic s-wave or multicomponent order parameter are called for. The magnetic field dependence of gamma(H) is neither linear for a fully gapped s-wave superconductor nor H(1/2) for nodal order parameter. It seems that this intriguing behavior of gamma(H) is associated with the intrinsic electronic properties other than flux pinning.
Collapse
Affiliation(s)
- H D Yang
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Samoc M, Samoc A, Luther-Davies B, Swiatkiewicz J, Jin CQ, White JW. Real and imaginary components of the third-order nonlinearity of polyaniline dodecylbenzenesulfonic salt. Opt Lett 1995; 20:2478. [PMID: 19865258 DOI: 10.1364/ol.20.002478] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
|
22
|
Gao JJ, Jin CQ. [Comparison of glucoside content of bitter apricot seeds processed in different ways and stored routinely for one year]. Zhongguo Zhong Yao Za Zhi 1992; 17:658-9, 702. [PMID: 1301751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- J J Gao
- Zhejiang Provincial Academy of Traditional Chinese Medicine, Hangzhou
| | | |
Collapse
|