Abstract
We have investigated effects of random substitution of proton sites with deuterons on the temperature- and pressure-induced phase transitions in squaric acid crystal, which consists of ferroelectrically ordered molecular sheets of [C4O4]2- (SQ2-) skeletons and intervening protons or deuterons. In the isotopically mixed crystals (H 1-xDx)2SQ, the critical temperature T c for the dielectric phase transition was found to increase linearly with the deuterium concentration x, while the critical pressure Pc increases nonlinearly with x at 300 K. Around the pressure ∼20 kbar above Pc, the constituent SQ2- skeletons in the paraelectric phase show a symmetry change from the asymmetric (C1h) to centrosymmetric (C4h) form, which is likely caused by the deformation of the correlated proton (deuteron) potential.
Original language | English |
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Pages (from-to) | 2244-2251 |
Number of pages | 8 |
Journal | The Journal of chemical physics |
Volume | 95 |
Issue number | 4 |
Publication status | Published - 1991 |
Externally published | Yes |
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ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
Cite this
Dielectric phase transition and symmetry change of constituent molecules in proton-deuteron mixed crystals of squaric acid. / Moritomo, Y.; Katsufuji, Takuro; Tokura, Y.
In: The Journal of chemical physics, Vol. 95, No. 4, 1991, p. 2244-2251.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dielectric phase transition and symmetry change of constituent molecules in proton-deuteron mixed crystals of squaric acid
AU - Moritomo, Y.
AU - Katsufuji, Takuro
AU - Tokura, Y.
PY - 1991
Y1 - 1991
N2 - We have investigated effects of random substitution of proton sites with deuterons on the temperature- and pressure-induced phase transitions in squaric acid crystal, which consists of ferroelectrically ordered molecular sheets of [C4O4]2- (SQ2-) skeletons and intervening protons or deuterons. In the isotopically mixed crystals (H 1-xDx)2SQ, the critical temperature T c for the dielectric phase transition was found to increase linearly with the deuterium concentration x, while the critical pressure Pc increases nonlinearly with x at 300 K. Around the pressure ∼20 kbar above Pc, the constituent SQ2- skeletons in the paraelectric phase show a symmetry change from the asymmetric (C1h) to centrosymmetric (C4h) form, which is likely caused by the deformation of the correlated proton (deuteron) potential.
AB - We have investigated effects of random substitution of proton sites with deuterons on the temperature- and pressure-induced phase transitions in squaric acid crystal, which consists of ferroelectrically ordered molecular sheets of [C4O4]2- (SQ2-) skeletons and intervening protons or deuterons. In the isotopically mixed crystals (H 1-xDx)2SQ, the critical temperature T c for the dielectric phase transition was found to increase linearly with the deuterium concentration x, while the critical pressure Pc increases nonlinearly with x at 300 K. Around the pressure ∼20 kbar above Pc, the constituent SQ2- skeletons in the paraelectric phase show a symmetry change from the asymmetric (C1h) to centrosymmetric (C4h) form, which is likely caused by the deformation of the correlated proton (deuteron) potential.
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M3 - Article
AN - SCOPUS:36449001669
VL - 95
SP - 2244
EP - 2251
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 4
ER -