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Bisht GS, Pal D. Spin-state transition of Co ion ( S=2 →S=5/2) in hole substituted 1D chain of Ca 3Co 2O 6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:285803. [PMID: 35447612 DOI: 10.1088/1361-648x/ac6924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
We have discovered spin-state transition (S= 2 toS= 5/2) of Co ions due to Mg substitution in the Ca3Co2O6apparent in the magnetic susceptibility, x-ray photoelectron spectroscopy (XPS), and first-principles study. We also examine the effect of Mg substitution on the magnetic and electronic structure of Ca3Co2O6by first-principles calculations. It involves generalized gradient approximation with Coulomb interaction (U) in exchange-correlation energy functional. Our study shows a reasonable agreement between effective magnetic moment (μeff) determined from the Curie-Weiss fit with that from the XPS analysis and first-principles calculations study. We have attributed the decrease in positive intra-chain exchange interaction constant (J1/kB) to the antiferromagnetically coupled induced Co4+ions (S= 5/2) arising from the Mg2+ions substitution. The in-field metamagnetic transitions in the isothermalM(H) curves below the critical field (Hc) have been accurately mapped and successfully explained by the change in magnetic entropy (ΔS) calculations and Arrott plots. Electronic structure study reveals hole-type doping of Mg atom, and the Fermi level (EF) shifts below. Density of state and band structure calculation indicates strong hybridization between partial states of Co-3d and O-2p orbitals for the Mg-doped compound due to which the band crossing at Fermi level is observed, and a hole-type Fermi surface is formed.
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Affiliation(s)
- Gajendra Singh Bisht
- Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - D Pal
- Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
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2
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Liu CB, Cheng JB, He JB, Chen R, Yue XY, Luo YS, Yang G, Zhou DW, Huang JS, Yu RM, Leng YM. Unusual magnetization process and magnetocaloric effect in α-CoV 2O 6driven by pulsed magnetic fields. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:435703. [PMID: 34343981 DOI: 10.1088/1361-648x/ac1a31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
In low-dimensional Ising spin systems, an interesting observation is the presence of step magnetization at low temperatures. Here we combine both DC and pulsed magnetic fields to study the 1/3 magnetization plateau and multiple steps in the Ising spin-chain material α-CoV2O6. Magnetization in pulsed fields is quite different from that in DC fields, showing multiple steps in an intermediate range of 4.2-6 K, inverted hysteresis below 4.2 K and asymmetric magnetization in negative fields below 11 K. We demonstrate that these unusual behaviors in magnetization are caused by the spin dynamics and the anomalous magnetocaloric effect (MCE) in α-CoV2O6, i.e., abrupt changes of sample temperature in adiabatic conditions. We successfully separate the influence between the intrinsic slow spin dynamics and the quasi-extrinsic temperature change. From the MCE, we find that some irreversible behavior is originated from the slow spin dynamics. Two different slow dynamics associated with the metastable steps are observed: one is sensitive to the slow field sweep rate at the order of ∼mT s-1and weakly depends on temperature, while the other responds to the rapid field sweep rate of ∼kT s-1and dominates at lowest temperature. We also distinguish that the metastable transition atH4is the first order and crucial for the ferrimagnetic to ferromagnetic transition. This study is useful to the understanding of multistep magnetization in α-CoV2O6and sheds light on recent experimental findings of related compounds.
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Affiliation(s)
- C B Liu
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - J B Cheng
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - J B He
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - R Chen
- Key Laboratory of Microelectronics and Energy of Henan Province, Henan Joint International Research Laboratory of New Energy Storage Technology, Xinyang Normal University, Xinyang 464000, People's Republic of China
| | - X Y Yue
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, People's Republic of China
| | - Y S Luo
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
- Key Laboratory of Microelectronics and Energy of Henan Province, Henan Joint International Research Laboratory of New Energy Storage Technology, Xinyang Normal University, Xinyang 464000, People's Republic of China
| | - G Yang
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - D W Zhou
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - J S Huang
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - R M Yu
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
| | - Y M Leng
- Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China
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3
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King AD, Raymond J, Lanting T, Isakov SV, Mohseni M, Poulin-Lamarre G, Ejtemaee S, Bernoudy W, Ozfidan I, Smirnov AY, Reis M, Altomare F, Babcock M, Baron C, Berkley AJ, Boothby K, Bunyk PI, Christiani H, Enderud C, Evert B, Harris R, Hoskinson E, Huang S, Jooya K, Khodabandelou A, Ladizinsky N, Li R, Lott PA, MacDonald AJR, Marsden D, Marsden G, Medina T, Molavi R, Neufeld R, Norouzpour M, Oh T, Pavlov I, Perminov I, Prescott T, Rich C, Sato Y, Sheldan B, Sterling G, Swenson LJ, Tsai N, Volkmann MH, Whittaker JD, Wilkinson W, Yao J, Neven H, Hilton JP, Ladizinsky E, Johnson MW, Amin MH. Scaling advantage over path-integral Monte Carlo in quantum simulation of geometrically frustrated magnets. Nat Commun 2021; 12:1113. [PMID: 33602927 PMCID: PMC7892843 DOI: 10.1038/s41467-021-20901-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/22/2020] [Indexed: 11/09/2022] Open
Abstract
The promise of quantum computing lies in harnessing programmable quantum devices for practical applications such as efficient simulation of quantum materials and condensed matter systems. One important task is the simulation of geometrically frustrated magnets in which topological phenomena can emerge from competition between quantum and thermal fluctuations. Here we report on experimental observations of equilibration in such simulations, measured on up to 1440 qubits with microsecond resolution. By initializing the system in a state with topological obstruction, we observe quantum annealing (QA) equilibration timescales in excess of one microsecond. Measurements indicate a dynamical advantage in the quantum simulation compared with spatially local update dynamics of path-integral Monte Carlo (PIMC). The advantage increases with both system size and inverse temperature, exceeding a million-fold speedup over an efficient CPU implementation. PIMC is a leading classical method for such simulations, and a scaling advantage of this type was recently shown to be impossible in certain restricted settings. This is therefore an important piece of experimental evidence that PIMC does not simulate QA dynamics even for sign-problem-free Hamiltonians, and that near-term quantum devices can be used to accelerate computational tasks of practical relevance.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ryan Li
- D-Wave Systems, Burnaby, BC, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Mohammad H Amin
- D-Wave Systems, Burnaby, BC, Canada.,Department of Physics, Simon Fraser University, Burnaby, BC, Canada
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4
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Leedahl B, Sundermann M, Amorese A, Severing A, Gretarsson H, Zhang L, Komarek AC, Maignan A, Haverkort MW, Tjeng LH. Origin of Ising magnetism in Ca 3Co 2O 6 unveiled by orbital imaging. Nat Commun 2019; 10:5447. [PMID: 31784516 PMCID: PMC6884600 DOI: 10.1038/s41467-019-13273-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/24/2019] [Indexed: 11/22/2022] Open
Abstract
The one-dimensional cobaltate Ca\documentclass[12pt]{minimal}
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\begin{document}$${}_{6}$$\end{document}6 is an intriguing material having an unconventional magnetic structure, displaying quantum tunneling phenomena in its magnetization. Using a newly developed experimental method, \documentclass[12pt]{minimal}
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\begin{document}$$s$$\end{document}s-core-level non-resonant inelastic x-ray scattering (\documentclass[12pt]{minimal}
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\begin{document}$$s$$\end{document}s-NIXS), we were able to image the atomic Co \documentclass[12pt]{minimal}
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\begin{document}$$3d$$\end{document}3d orbital that is responsible for the Ising magnetism in this system. We can directly observe that corrections to the commonly accepted ideal prismatic trigonal crystal field scheme occur in Ca\documentclass[12pt]{minimal}
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\begin{document}$${}_{6}$$\end{document}6, and it is the complex \documentclass[12pt]{minimal}
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\begin{document}$${d}_{2}$$\end{document}d2 orbital occupied by the sixth electron at the high-spin Co\documentclass[12pt]{minimal}
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\begin{document}$${}_{\,\text{trig}\,}^{3+}$$\end{document}trig3+ (\documentclass[12pt]{minimal}
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\begin{document}$${d}^{6}$$\end{document}d6) sites that generates the Ising-like behavior. The ability to directly relate the orbital occupation with the local crystal structure is essential to model the magnetic properties of this system. Ca\documentclass[12pt]{minimal}
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\begin{document}$${}_{3}$$\end{document}3Co\documentclass[12pt]{minimal}
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\begin{document}$${}_{6}$$\end{document}6 has an unconventional magnetic structure displaying quantum tunnelling phenomena in its magnetization. Here, the authors use s-core-level non-resonant inelastic X-ray scattering to image the atomic Co 3d orbital that is responsible for the Ising magnetism in this system.
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Affiliation(s)
- Brett Leedahl
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Martin Sundermann
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany.,Institute of Physics II, University of Cologne, Zülpicher Straße 77, 50937, Cologne, Germany
| | - Andrea Amorese
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany.,Institute of Physics II, University of Cologne, Zülpicher Straße 77, 50937, Cologne, Germany
| | - Andrea Severing
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany.,Institute of Physics II, University of Cologne, Zülpicher Straße 77, 50937, Cologne, Germany
| | - Hlynur Gretarsson
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany.,PETRA III, Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607, Hamburg, Germany
| | - Lunyong Zhang
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Alexander C Komarek
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Antoine Maignan
- Laboratoire CRISMAT, UMR 6508 CNRS-ENSICAEN, 6 bd Maréchal Juin, 14050, Caen Cedex, France
| | - Maurits W Haverkort
- Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120, Heidelberg, Germany
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany.
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5
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Baumbach RE, Hamlin JJ, Janoschek M, Singleton J, Maple MB. Frustrated magnetism in the spin-chain metal Yb2Fe12P7. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:046004. [PMID: 26742679 DOI: 10.1088/0953-8984/28/4/046004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnetization measurements for magnetic fields [Formula: see text] up to 60 T are reported for the noncentrosymmetric spin-chain metal Yb2Fe12P7. These measurements reveal behavior that is consistent with Ising-like spin chain magnetism that produces pronounced spin degeneracy. In particular, we find that although a Brillouin field dependence is observed in M(H) for [Formula: see text] with a saturation moment that is close to the expected value for free ions of Yb(3+) , non-Brillouin-like behavior is seen for [Formula: see text] with an initial saturation moment that is nearly half the free ion value. In addition, hysteretic behavior that extends above the ordering temperature [Formula: see text] is seen for [Formula: see text] but not for [Formula: see text], suggesting out-of-equilibrium physics. This point of view is strengthened by the observation of a spin reconfiguration in the ordered state for [Formula: see text] which is only seen for [Formula: see text] and after polarizing the spins. Together with the heat capacity data, these results suggest that the anomalous low temperature phenomena that were previously reported (Baumbach 2010 et al Phys. Rev. Lett. 105 106403) are driven by spin degeneracy that is related to the Ising-like one dimensional chain-like configuration of the Yb ions.
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Affiliation(s)
- R E Baumbach
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
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6
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Wang Z, Kamiya Y, Nevidomskyy AH, Batista CD. Three-Dimensional Crystallization of Vortex Strings in Frustrated Quantum Magnets. PHYSICAL REVIEW LETTERS 2015; 115:107201. [PMID: 26382699 DOI: 10.1103/physrevlett.115.107201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate that frustrated exchange interactions can produce exotic 3D crystals of vortex strings near the saturation field (H=H(sat)) of body- and face-centered cubic Mott insulators. The combination of cubic symmetry and frustration leads to a magnon spectrum of the fully polarized spin state (H>H(sat)) with degenerate minima at multiple noncoplanar Q vectors. This spectrum becomes gapless at the quantum critical point H=H(sat) and the magnetic ordering below H(sat) can be formally described as a condensate of a dilute gas of bosons. By expanding in the lattice gas parameter, we find that different vortex crystals span sizable regions of the phase diagrams for isotropic exchange and are further stabilized by symmetric exchange anisotropy.
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Affiliation(s)
- Zhentao Wang
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - Yoshitomo Kamiya
- iTHES Research Group and Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | | | - Cristian D Batista
- Theoretical Division, T-4 and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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7
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Frustration-induced nanometre-scale inhomogeneity in a triangular antiferromagnet. Nat Commun 2015; 5:3222. [PMID: 24477185 PMCID: PMC4273263 DOI: 10.1038/ncomms4222] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 01/08/2014] [Indexed: 11/08/2022] Open
Abstract
Phase inhomogeneity of otherwise chemically homogenous electronic systems is an essential ingredient leading to fascinating functional properties, such as high-Tc superconductivity in cuprates, colossal magnetoresistance in manganites and giant electrostriction in relaxors. In these materials distinct phases compete and can coexist owing to intertwined ordered parameters. Charge degrees of freedom play a fundamental role, although phase-separated ground states have been envisioned theoretically also for pure spin systems with geometrical frustration that serves as a source of phase competition. Here we report a paradigmatic magnetostructurally inhomogenous ground state of the geometrically frustrated α-NaMnO2 that stems from the system's aspiration to remove magnetic degeneracy and is possible only due to the existence of near-degenerate crystal structures. Synchrotron X-ray diffraction, nuclear magnetic resonance and muon spin relaxation show that the spin configuration of a monoclinic phase is disrupted by magnetically short-range-ordered nanoscale triclinic regions, thus revealing a novel complex state of matter.
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8
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Magnetic inhomogeneity on a triangular lattice: the magnetic-exchange versus the elastic energy and the role of disorder. Sci Rep 2015; 5:9272. [PMID: 25786810 PMCID: PMC4365415 DOI: 10.1038/srep09272] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/23/2015] [Indexed: 11/08/2022] Open
Abstract
Inhomogeneity in the ground state is an intriguing, emergent phenomenon in magnetism. Recently, it has been observed in the magnetostructural channel of the geometrically frustrated α-NaMnO2, for the first time in the absence of active charge degrees of freedom. Here we report an in-depth numerical and local-probe experimental study of the isostructural sister compound CuMnO2 that emphasizes and provides an explanation for the crucial differences between the two systems. The experimentally verified, much more homogeneous, ground state of the stoichiometric CuMnO2 is attributed to the reduced magnetoelastic competition between the counteracting magnetic-exchange and elastic-energy contributions. The comparison of the two systems additionally highlights the role of disorder and allows the understanding of the puzzling phenomenon of phase separation in uniform antiferromagnets.
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9
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Impact of spin-orbit coupling on the magnetism of Sr₃MIrO₆ (M = Ni, Co). Sci Rep 2014; 4:4609. [PMID: 24714376 PMCID: PMC3980219 DOI: 10.1038/srep04609] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/21/2014] [Indexed: 11/09/2022] Open
Abstract
Iridates are of current great interest for their entangled spin-orbital state and possibly exotic properties. In this work, using density functional calculations, we have demonstrated that the hexagonal spin-chain materials Sr3MIrO6 (M = Ni, Co) are an iridate system in which the spin-orbit coupling (SOC) tunes the magnetic and electronic properties. The significant SOC alters the orbital state, the exchange pathway, and thus the magnetic structure. This work clarifies the nature and the origin of the intra-chain antiferromagnetism of Sr3MIrO6 and well accounts for the most recent experiments.
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10
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Basu T, Singh K, Sampathkumaran EV. Modifications in the frustrated magnetism, oxidation state of Co and magnetoelectric coupling effects induced by a partial replacement of Ca by Gd in the spin-chain compound Ca3Co2O6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:496013. [PMID: 24222434 DOI: 10.1088/0953-8984/25/49/496013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have systematically investigated the influence of the gradual replacement of Ca by Gd on the magnetic and complex dielectric properties of the well-known geometrically frustrated spin-chain system Ca3Co2O6 (TN = 24 K with additional magnetic transitions below 12 K), by studying the series Ca3−xGdxCo2O6 (x ≤ 0.7), down to 1.8 K. Heat-capacity measurements establish that the reduction of TN with Gd substitution is much less compared to that by Y substitution. The magnetic moment data reveal that there are changes in the oxidation state of Co as well, unlike for Y substitution, beyond x = 0.2. Thus, despite being isovalent, both these substitutions interestingly differ in changing these magnetic properties in these oxides. We propose that the valence electrons of Y and those of R ions play different roles in deciding the magnetic characteristics of these mixed oxides. It is observed that a small amount (x = 0.3) of Gd substitution for Ca is enough to suppress glassy ac magnetic susceptibility behavior for the peak around 12 K. An additional low-temperature magnetic anomaly close to 5 K gets more prominent with increasing Gd concentration as revealed by heat-capacity data. Trends in temperature dependence of complex dielectric behavior were also tracked with varying composition and a frequency dependence is observed, not only for the transition in the region around 10 K (for some compositions), but also for the 5 K transition which is well resolved for a higher concentration of Gd. Thus, the Gd-substituted Ca3Co2O6 series is shown to reveal interesting magnetic and dielectric behaviors of this family of oxides.
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11
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Basu T, Iyer KK, Singh K, Sampathkumaran EV. Novel dielectric anomalies due to spin-chains above and below Néel temperature in Ca3Co2O6. Sci Rep 2013; 3:3104. [PMID: 24173211 PMCID: PMC3813931 DOI: 10.1038/srep03104] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 10/16/2013] [Indexed: 11/30/2022] Open
Abstract
We bring out novel dielectric behavior of a spin-chain compound, Ca3Co2O6, undergoing Néel order at (TN = ) 24 K. It is found that the virgin curve in the plot of isothermal dielectric constant (ε') versus magnetic-field lies outside the ‘butterfly-shaped’ envelope curve well below TN (e.g., 2.6 K), with a signature of a partial arrest of the high-field magnetoelectric (ME) phase in zero-field after travelling through magnetic-field-induced magnetic transitions. This behavior is in contrast to that observed in the isothermal magnetization data. Thus, this work brings out a novel case for ‘phase-coexistence phenomenon’ due to ME coupling. Another strange finding is that there is a weak, but a broad, peak in ε' around 85–115 K well above TN, attributable to incipient spin-chain magnetic ordering. This finding should inspire further work to study ME coupling on artificial assemblies of magnetic chains, also keeping in mind miniaturization required for possible applications.
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Affiliation(s)
- Tathamay Basu
- Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai - 400005, India
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12
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Wei T, Huang YH, Zeng R, Yuan LX, Hu XL, Zhang WX, Jiang L, Yang JY, Zhang ZL. Evaluation of Ca3Co2O6 as cathode material for high-performance solid-oxide fuel cell. Sci Rep 2013; 3:1125. [PMID: 23350032 PMCID: PMC3553459 DOI: 10.1038/srep01125] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/14/2012] [Indexed: 11/23/2022] Open
Abstract
A cobalt-based thermoelectric compound Ca3Co2O6 (CCO) has been developed as new cathode material with superior performance for intermediate-temperature (IT) solid-oxide fuel cell (SOFC). Systematic evaluation has been carried out. Measurement of thermal expansion coefficient (TEC), thermal-stress (σ) and interfacial shearing stress (τ) with the electrolyte show that CCO matches well with several commonly-used IT electrolytes. Maximum power density as high as 1.47 W cm−2 is attained at 800°C, and an additional thermoelectric voltage of 11.7 mV is detected. The superior electrochemical performance, thermoelectric effect, and comparable thermal and mechanical behaviors with the electrolytes make CCO to be a promising cathode material for SOFC.
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Affiliation(s)
- Tao Wei
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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