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Ohwada, Kenji; Ishii, Kenji; Inami, Toshiya; Murakami, Youichi; Shobu, Takahisa; Ohsumi, H.; Ikeda, Naoshi; Ohishi, Yasuo

doi:10.1103/physrevb.72.014123

Cited by 29 publications

(34 citation statements)

References 26 publications

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“…In order to study structural evolution under pressure, a hydrostatic pressure was applied from 0 to ∼42 GPa, and all the bond lengths and bond angles were measured (in the calculated structure) as a function of pressure. Similar to other Cu−Cl hybrid perovskites 19,22 of this family, (EDBE)- …”

Section: ■ Results and Discussionmentioning

confidence: 91%

“…In this structure, c and b are equivalent directions in the plane of Cu− Cl sheet (Figure 1a) and ideally the compressions should be the same along these two directions. Such anisotropic compressibility has been reported in other materials of this family, e.g., in (C 2 H 5 NH 3 ) 2 CuCl 4 (EA 2 CuCl 4 ), 19 and also in transition-metal complex of type MX 6 (where M is the transition metal and X is the ligand), like in LaSrMnO 4 20 and LaMnO 3 . 21 Gossling et al 20 hypothesized that the anisotropic compressibility is due to changes in orbital occupation of the material, i.e., the shrinkage of the c-axis lattice parameter occurs due to filling of the upper Hubbard band.…”

Section: Inorganic Chemistrymentioning

confidence: 91%

“…J−T distortion as reported in previous studies is found to be suppressed by the pressure; however, the value of critical pressure (P c ) at which complete J−T distortion suppression occurs is highly debated. [17][18][19]22,23 In order to understand the origin of J−T distortion suppression with pressure, we measured R (Cu−Cl)axial and R (Cu−Cl)eq at different pressures. J−T distortion suppression occurs at the pressure at which R (Cu−Cl)axial becomes equal to R (Cu−Cl)eq .…”

Section: Inorganic Chemistrymentioning

confidence: 99%

“…Moreover, Cu−Cl hybrid perovskite also has a distinctive magnetic property. They show hole− orbital ordering 19 and behave as two-dimensional ferromagnets (T c ≈ 10 K). 28 To the best of our knowledge, the effect of pressure on the magnetic ordering in this material has not been reported.…”

Section: ■ Introductionmentioning

confidence: 99%

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Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

2016

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While pressure-induced changes in the electronic, magnetic, and optical properties of Cu-Cl hybrid perovskites have been studied intensively, the correlation between these properties and pressure-induced structural changes is still vaguely understood. Here, by first-principles calculations on a model system (EDBE)[CuCl4] (EDBE = 2,2'-(ethylenedioxy)bis(ethylammonium)) (a Cu-Cl hybrid perovskite), we correlate the evolution of a series of exciting physical properties with pressure while resolving some of the long-standing debates on the fundamental electronic nature of this important class of material. The material shows two structural phase transitions and an anisotropy in compressibility with increasing pressure. After a critical pressure of 17 GPa, the structure becomes highly symmetric, thereby suppressing the Jahn-Teller distortions. At zero pressure, mapping the optical transitions with the Laporte selection rules, lower and higher energy excitations are found to be of Mott-Hubbard (MH) and charge transfer (CT) type, respectively, signifying the material to be a Mott insulator. The material shows a red shift in the charge transfer band edge with increasing pressure and temperature, demonstrating the piezochromism and the thermochromism, respectively. Piezochromism originates from the changes in mixing of Cl-Cu p-d states, while thermochromism is due to broadening of conduction band states, thereby showing different electronic and structural evolution with pressure and temperature. Furthermore, the magnetic ordering in the material was found to be stable up to higher pressures, making pressure a tool to tune the electronic property without perturbing the magnetic property.

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Section: ■ Results and Discussionmentioning

confidence: 91%

Section: Inorganic Chemistrymentioning

confidence: 91%

Section: Inorganic Chemistrymentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

2016

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“…A nonmagnetic semi-conducting nature is observed for Pb while the Cd and Zn analogues show insulating behaviour 18 . The crystal structure varies with temperature and pressure [19][20][21] . All compounds of this series show orthorhombic structure at room temperature and undergo a series of structural changes due to different arrangements of alkyl ammonium chains.…”

Section: Introductionmentioning

confidence: 99%

Dielectric and Raman investigations of structural phase transitions in (C₂H₅NH₃)₂CdCl₄

Yadav

Swain

Kundu

et al. 2015

Phys. Chem. Chem. Phys.

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Temperature-dependent Raman and dielectric measurements have been carried out on (C2H5NH3)2CdCl4 single crystals. Raman studies reveal the presence of two structural phase transitions below room temperature at 216 K and 114 K. The phase transitions are marked by anomalies in temperature dependence of wave-number and full width half maximum (FWHM) of several vibrational modes. The transitions are also accompanied by anomalies in dielectric measurements. Raman and dielectric data indicate that the transition at 216 K is order-disorder in nature and is driven by re-orientation of organic ions, while the transition at 114 K is due to coupling between the CdCl6 octahedron and the organic chain. Further high temperature dielectric measurements reveal the presence of one more structural phase transition around 473 K across which dispersion in dielectric parameters is observed. The activation energies and relaxation time obtained for high temperature dielectric phases are characteristic of combined reorientation motions of alkyl ammonium cations.

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High Compression‐Induced Conductivity in a Layered Cu–Br Perovskite

et al. 2020

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We show that the onset pressure for appreciable conductivity in layered copper‐halide perovskites can decrease by ca. 50 GPa upon replacement of Cl with Br. Layered Cu–Cl perovskites require pressures >50 GPa to show a conductivity of 10−4 S cm−1, whereas here a Cu–Br congener, (EA)2CuBr4 (EA=ethylammonium), exhibits conductivity as high as 2×10−3 S cm−1 at only 2.6 GPa, and 0.17 S cm−1 at 59 GPa. Substitution of higher‐energy Br 4p for Cl 3p orbitals lowers the charge‐transfer band gap of the perovskite by 0.9 eV. This 1.7 eV band gap decreases to 0.3 eV at 65 GPa. High‐pressure X‐ray diffraction, optical absorption, and transport measurements, and density functional theory calculations allow us to track compression‐induced structural and electronic changes. The notable enhancement of the Br perovskite's electronic response to pressure may be attributed to more diffuse Br valence orbitals relative to Cl orbitals. This work brings the compression‐induced conductivity of Cu‐halide perovskites to more technologically accessible pressures.

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Structural properties and phase transition of hole-orbital-ordered(C2H5NH3)2

Cited by 29 publications

References 26 publications

Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

Dielectric and Raman investigations of structural phase transitions in (C₂H₅NH₃)₂CdCl₄

High Compression‐Induced Conductivity in a Layered Cu–Br Perovskite

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Structural properties and phase transition of hole-orbital-ordered(C2H5NH3)2

Cited by 29 publications

References 26 publications

Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

Suppression of Jahn–Teller Distortions and Origin of Piezochromism and Thermochromism in Cu–Cl Hybrid Perovskite

Dielectric and Raman investigations of structural phase transitions in (C2H5NH3)2CdCl4

High Compression‐Induced Conductivity in a Layered Cu–Br Perovskite

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Product

Resources

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Dielectric and Raman investigations of structural phase transitions in (C₂H₅NH₃)₂CdCl₄