Dielectric phase transition and symmetry change of constituent molecules in proton-deuteron mixed crystals of squaric acid
In: Scopus-Elsevier
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Zugriff:
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 (H1−xDx )2SQ, the critical temperature Tc 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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Dielectric phase transition and symmetry change of constituent molecules in proton-deuteron mixed crystals of squaric acid
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Autor/in / Beteiligte Person: | Katsufuji, Takuro ; Tokura, Yasuhiro ; Moritomo, Yutaka |
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Quelle: | Scopus-Elsevier |
Medientyp: | unknown |
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