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Koborinai R, Dissanayake SE, Reehuis M, Matsuda M, Kajita T, Kuwahara H, Lee SH, Katsufuji T. Orbital Glass State of the Nearly Metallic Spinel Cobalt Vanadate. Phys Rev Lett 2016; 116:037201. [PMID: 26849610 DOI: 10.1103/physrevlett.116.037201] [Citation(s) in RCA: 3] [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] [Received: 04/27/2015] [Indexed: 06/05/2023]
Abstract
Strain, magnetization, dielectric relaxation, and unpolarized and polarized neutron diffraction measurements were performed to study the magnetic and structural properties of spinel Co_{1-x}V_{2+x}O_{4}. The strain measurement indicates that, upon cooling, ΔL/L in the order of ∼10^{-4} starts increasing below T_{C}, becomes maximum at T_{max}, and then decreases and changes its sign at T^{*}. Neutron measurements indicate that a collinear ferrimagnetic order develops below T_{C} and upon further cooling noncollinear ferrimagnetic ordering occurs below T_{max}. At low temperatures, the dielectric constant exhibits a frequency dependence, indicating slow dynamics. These results indicate the existence of an orbital glassy state at low temperatures in this nearly metallic frustrated magnet.
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Affiliation(s)
- R Koborinai
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
| | - S E Dissanayake
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
| | - M Reehuis
- Helmholtz-Zentrum für Materialien und Energie, 14109 Berlin, Germany
| | - M Matsuda
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Kajita
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
| | - H Kuwahara
- Department of Physics, Sophia University, Tokyo 102-8554, Japan
| | - S-H Lee
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
| | - T Katsufuji
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
- Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, Tokyo 169-0051, Japan
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Takayama K, Koyama T, Mori S, Kato K, Takata M, Fujioka J, Tokura Y, Miyazaki J, Katsufuji T. Electronic phase transition and an anomalous ordered phase in Ba2Ti13O22 with 3d1 ions on a triangle-based lattice. Phys Rev Lett 2013; 110:196405. [PMID: 23705727 DOI: 10.1103/physrevlett.110.196405] [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] [Received: 02/12/2013] [Indexed: 06/02/2023]
Abstract
We found that Ba(2)Ti(13)O(22) with Ti(3+) (3d(1)) ions on a triangle-based lattice exhibits a phase transition at T(c)~200 K, below which the increase of electrical resistivity and decrease of magnetic susceptibility were observed. Transmission electron microscopy and optical reflectivity measurements indicate that the low-temperature phase of the present compound shares characteristics in common with a charge-density-wave state with remnant carriers, although a commensurate wave vector of the modulation and a linear temperature dependence of the magnetic susceptibility below T(c) suggest an exotic ordered state.
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Affiliation(s)
- K Takayama
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
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Kobayashi K, Koyama T, Horibe Y, Katsufuji T, Cheong SW, Mori S. Ferroelectric and Structural Antiphase Domains in Hexagonal RMnO3. ACTA ACUST UNITED AC 2012. [DOI: 10.1557/opl.2012.448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe have investigated characteristic ferroelectric and structural antiphase domain structures in single crystals of hexagonal RMnO3 (R=Y, Ho, Lu, and Yb) by obtaining various electron diffraction patterns, dark-filed images and high-resolution lattice images. In the ferroelectric phase of RMnO3 characteristic domain structures consisting of six ferroelectric and structural antiphase domains, which can be identified as the “cloverleaf” pattern, is found in the (110) plane, in addition to the (001) plane, and are inherent to the ferroelectric phase of hexagonal RMnO3. In domain configuration with the cloverleaf pattern in the (110) plane, the structural antiphase boundaries are inclined to be parallel to the [001] direction.
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Miyazaki J, Matsudaira K, Shimizu Y, Itoh M, Nagamine Y, Mori S, Kim JE, Kato K, Takata M, Katsufuji T. Formation of a three-dimensional network of V trimers in A2V13O22 (A=Ba, Sr). Phys Rev Lett 2010; 104:207201. [PMID: 20867054 DOI: 10.1103/physrevlett.104.207201] [Citation(s) in RCA: 2] [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: 02/03/2010] [Indexed: 05/29/2023]
Abstract
We found that in A2V13O22 (A=Ba, Sr), which contains a trilayer slab of VO in the sodium-chloride structure with periodically missing ions, the trimerization of V ions occurs at 290 K (A=Ba) and 380 K (A=Sr). V trimers form a three-dimensional network, but some V ions remain untrimerized in these compounds. The suppression of magnetic susceptibility with trimerization and the existence of a Curie tail at low temperatures, together with the result of NMR measurement, indicate that the V trimers are spin singlet, whereas the untrimerized V ions have a magnetic moment; i.e., there is a spontaneous separation between nonmagnetic and magnetic ions in the crystal.
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Affiliation(s)
- J Miyazaki
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
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Suzuki T, Katsumura M, Taniguchi K, Arima T, Katsufuji T. Orbital ordering and magnetic field effect in MnV2O4. Phys Rev Lett 2007; 98:127203. [PMID: 17501154 DOI: 10.1103/physrevlett.98.127203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Indexed: 05/15/2023]
Abstract
We studied the structural properties of an orbital-spin-coupled spinel oxide, MnV2O4, mainly by single-crystal x-ray diffraction measurement. It was found that a structural phase transition from cubic to tetragonal and ferrimagnetic ordering occur at the same temperature (Ts,TN=57 K). The structural phase transition was induced also by magnetic field above Ts. In addition, magnetic-field-induced alignment of tetragonal domains results in large magnetostriction below Ts. We also found that the structural phase transition is caused by the antiferro-type ordering of the V t2g orbitals.
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Affiliation(s)
- T Suzuki
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
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6
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Horibe Y, Shingu M, Kurushima K, Ishibashi H, Ikeda N, Kato K, Motome Y, Furukawa N, Mori S, Katsufuji T. Spontaneous formation of vanadium "molecules" in a geometrically frustrated crystal: AlV2O4. Phys Rev Lett 2006; 96:086406. [PMID: 16606207 DOI: 10.1103/physrevlett.96.086406] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Indexed: 05/08/2023]
Abstract
We investigated the charge-ordered (CO) state in spinel AlV2O4 by electron diffraction, synchrotron x-ray diffraction, and magnetic measurements. It was found that the CO structure appearing below 700 K is characterized by the formation of V clusters (heptamers), each of which is consisting of 7 vanadium atoms and is in a spin-singlet state as a total. Theoretical consideration indicates that this unique molecularlike V heptamer is stabilized by a strong bonding of vanadium t(2g) orbitals.
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Affiliation(s)
- Y Horibe
- Department of Physics, Osaka Prefecture University, Osaka 599-8531, Japan
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Iwasawa H, Yamakawa K, Saitoh T, Inaba J, Katsufuji T, Higashiguchi M, Shimada K, Namatame H, Taniguchi M. Electronic structure of charge- and spin-controlled Sr(1-(x+y))La(x+y)Ti(1-x)Cr(x)O3. Phys Rev Lett 2006; 96:067203. [PMID: 16606039 DOI: 10.1103/physrevlett.96.067203] [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] [Received: 08/30/2005] [Indexed: 05/08/2023]
Abstract
We present the electronic structure of Sr(1-(x+y))La(x+y)Ti(1-x)Cr(x)O3 investigated by high-resolution photoemission spectroscopy. In the vicinity of the Fermi level, it was found that the electronic structure was composed of a Cr 3d local state with the t(2g)3 configuration and a Ti 3d itinerant state. The energy levels of these Cr and Ti 3d states are well interpreted by the difference of the charge-transfer energy of both ions. The spectral weight of the Cr 3d state is completely proportional to the spin concentration x irrespective of the carrier concentration y, indicating that the spin density can be controlled by x as desired. In contrast, the spectral weight of the Ti 3d state is not proportional to y, depending on the amount of Cr doping.
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Affiliation(s)
- H Iwasawa
- Department of Applied Physics, Tokyo University of Science, Shinjuku-ku, Tokyo 162-8601, Japan
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Adachi K, Suzuki T, Kato K, Osaka K, Takata M, Katsufuji T. Magnetic-field switching of crystal structure in an orbital-spin-coupled system: MnV2O4. Phys Rev Lett 2005; 95:197202. [PMID: 16384017 DOI: 10.1103/physrevlett.95.197202] [Citation(s) in RCA: 5] [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: 04/26/2005] [Indexed: 05/05/2023]
Abstract
We studied the magnetic and structural properties of spinel MnV2O4, which has S=5/2 spin with no orbital degrees of freedom on the Mn2+ site and S=1 spin and three orbital degrees of freedom on the V3+ site. We found that the ferrimagnetic ordering at TN=56.5K and the structural phase transition at Ts=53.5K are closely correlated in this compound and found a switching of crystal structure between cubic and tetragonal phases by the magnetic field. This phenomenon can be explained by the coupling between orbital and spin degrees of freedom in the t2g states of the V site.
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Affiliation(s)
- K Adachi
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
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Matsuno K, Katsufuji T, Mori S, Nohara M, Machida A, Moritomo Y, Kato K, Nishibori E, Takata M, Sakata M, Kitazawa K, Takagi H. Charge ordering and spin frustration in AlV2-x CrxO4. Phys Rev Lett 2003; 90:096404. [PMID: 12689246 DOI: 10.1103/physrevlett.90.096404] [Citation(s) in RCA: 4] [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] [Received: 08/31/2002] [Indexed: 05/24/2023]
Abstract
The relationship between charge and spin degrees of freedom in a geometrically frustrated system, AlV2-xCrxO4 spinel, is investigated. Upon Cr doping, the charge-ordered phase of AlV2O4 is rapidly suppressed and a charge-disordered phase grows up instead. It is found that the magnetic ground state is a spin-glass state dominated by geometrical frustration for both phases, but larger spin entropy remains down to low temperatures in the charge-ordered phase, possibly owing to its two-dimensional character.
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Affiliation(s)
- K Matsuno
- Department of Advanced Materials Science, University of Tokyo, Tokyo 113-8656, Japan
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Spälter S, Hwang HY, Zimmermann J, Lenz G, Katsufuji T, Cheong SW, Slusher RE. Strong self-phase modulation in planar chalcogenide glass waveguides. Opt Lett 2002; 27:363-365. [PMID: 18007804 DOI: 10.1364/ol.27.000363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Single-mode planar waveguides were fabricated from chalcogenide glass compounds with large Kerr nonlinearities. Strong self-phase modulation of subpicosecond pulses along with low linear and nonlinear absorption losses demonstrates the potential for ultrafast, low-power, all-optical processing applications.
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Hildebrand MG, Reedyk M, Katsufuji T, Tokura Y. Far-infrared resonance in Sr(2)RuO(4). Phys Rev Lett 2001; 87:227002. [PMID: 11736419 DOI: 10.1103/physrevlett.87.227002] [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] [Received: 10/19/2000] [Indexed: 05/23/2023]
Abstract
The far-infrared c-axis reflectance of Sr(2)RuO(4) has been measured above and below the 2.5 K superconducting transition temperature of the sample. A plasma edge develops near 70 cm(-1) as the temperature is lowered, which corresponds to a Drude peak in the real optical conductivity associated with the onset of the coherent motion of the carriers. A gaplike suppression of the frequency-dependent scattering rate at low temperatures indicates that the coherent transport is related to a loss of scattering below 60 cm(-1). A strong resonance near 9 meV is responsible for the scattering that destroys coherence.
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Affiliation(s)
- M G Hildebrand
- Department of Physics, Brock University, St. Catharines, Ontario, Canada L2S 3A1
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Katsufuji T, Hwang H, Cheong SW. Anomalous magnetotransport properties of R2Mo2O7 near the magnetic phase boundary. Phys Rev Lett 2000; 84:1998-2001. [PMID: 11017680 DOI: 10.1103/physrevlett.84.1998] [Citation(s) in RCA: 4] [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] [Received: 07/23/1999] [Indexed: 05/23/2023]
Abstract
The magnetic and transport properties of pyrochlore R2Mo2O7 have been studied with variation of the rare earth ( R). The change of the mean ionic radius of R, which induces change of the lattice structure, determines the magnetic ground state (ferromagnetic or spin glass), and the magnetic phase boundary is correlated with the metal-insulator crossover. Furthermore, we found enhanced magnetoresistance and unusual residual anomalous Hall effect at low temperatures near the phase boundary, which can be attributed to the coexistence of both phases.
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Affiliation(s)
- T Katsufuji
- Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974, USA
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Lenz G, Zimmermann J, Katsufuji T, Lines ME, Hwang HY, Spälter S, Slusher RE, Cheong SW, Sanghera JS, Aggarwal ID. Large Kerr effect in bulk Se-based chalcogenide glasses. Opt Lett 2000; 25:254-256. [PMID: 18059846 DOI: 10.1364/ol.25.000254] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
High-speed optical communication requires ultrafast all-optical processing and switching capabilities. The Kerr nonlinearity, an ultrafast optical nonlinearity, is often used as the basic switching mechanism. A practical, small device that can be switched with ~1-pJ energies requires a large Kerr effect with minimal losses (both linear and nonlinear). We have investigated theoretically and experimentally a number of Se-based chalcogenide glasses. We have found a number of compounds with a Kerr nonlinearity hundreds of times larger than silica, making them excellent candidates for ultrafast all-optical devices.
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Katsufuji T, Tanabe T, Ishikawa T, Fukuda Y, Arima T, Tokura Y. Optical spectroscopy of the charge-ordering transition in La1.67Sr0.33NiO4. Phys Rev B Condens Matter 1996; 54:R14230-R14233. [PMID: 9985494 DOI: 10.1103/physrevb.54.r14230] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Katsufuji T, Okimoto Y, Tokura Y. Spectral weight transfer of the optical conductivity in doped Mott insulators. Phys Rev Lett 1995; 75:3497-3500. [PMID: 10059601 DOI: 10.1103/physrevlett.75.3497] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Inaba F, Arima T, Ishikawa T, Katsufuji T, Tokura Y. Change of electronic properties on the doping-induced insulator-metal transition in La1-xSrxVO3. Phys Rev B Condens Matter 1995; 52:R2221-R2224. [PMID: 9981376 DOI: 10.1103/physrevb.52.r2221] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Okimoto Y, Katsufuji T, Ishikawa T, Urushibara A, Arima T, Tokura Y. Anomalous variation of optical spectra with spin polarization in double-exchange ferromagnet: La1-xSrxMnO3. Phys Rev Lett 1995; 75:109-112. [PMID: 10059127 DOI: 10.1103/physrevlett.75.109] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Okimoto Y, Katsufuji T, Okada Y, Arima T, Tokura Y. Optical spectra in (La,Y)TiO3: Variation of Mott-Hubbard gap features with change of electron correlation and band filling. Phys Rev B Condens Matter 1995; 51:9581-9588. [PMID: 9977620 DOI: 10.1103/physrevb.51.9581] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Katsufuji T, Okimoto Y, Arima T, Tokura Y, Torrance JB. Optical spectroscopy of the metal-insulator transition in NdNiO3. Phys Rev B Condens Matter 1995; 51:4830-4835. [PMID: 9979351 DOI: 10.1103/physrevb.51.4830] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Katsufuji T, Tokura Y. Anomalous variation of phonon Raman intensities near the metal-to-Mott-insulator transition in titanium oxide systems. Phys Rev B Condens Matter 1994; 50:2704-2707. [PMID: 9976503 DOI: 10.1103/physrevb.50.2704] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Katsufuji T, Tokura Y. Electronic Raman scattering in filling-controlled metals: Sr1-xLaxTiO3. Phys Rev B Condens Matter 1994; 49:4372-4375. [PMID: 10011349 DOI: 10.1103/physrevb.49.4372] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Katsufuji T, Tokura Y, Ido T, Uchida S. Symmetry-dependent electronic Raman scattering in La2-xSrxCuO4: Evidence for doping-induced change in the k-space anisotropy of charge dynamics. Phys Rev B Condens Matter 1993; 48:16131-16134. [PMID: 10008185 DOI: 10.1103/physrevb.48.16131] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Moritomo Y, Katsufuji T, Tokura Y. Dielectric phase transition and symmetry change of constituent molecules in proton–deuteron mixed crystals of squaric acid. J Chem Phys 1991. [DOI: 10.1063/1.460980] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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