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Calorimetric measurements of the phase transition in Rochelle salt–ammonium Rochelle salt mixed crystals
Title: | Calorimetric measurements of the phase transition in Rochelle salt–ammonium Rochelle salt mixed crystals |
Authors: | Noda, N. Browse this author | Nozaki, R. Browse this author | Shiozaki, Y. Browse this author |
Issue Date: | 1-Nov-2000 |
Publisher: | American Physical Society |
Journal Title: | Physical Review B |
Volume: | 62 |
Issue: | 18 |
Start Page: | 12040 |
End Page: | 12044 |
Publisher DOI: | 10.1103/PhysRevB.62.12040 |
Abstract: | The specific heats, which are given with absolute value, of Rochelle salt–ammonium Rochelle salt mixed crystals (RS1-x−ARSx) in a region 0.18<~x<~0.9 have been measured between about 10 K and 300 K by an ac calorimetric method. A very small anomaly was found around the transition for any x. It becomes larger as x increases. The anomalies have been well described using the Landau-type free energy expanded to the sixth order of polarization. It was found that, as x increases, the transition point approaches the tricritical point at which a crossover from the second-order phase transition to the first-order one takes place. Transition entropy has been calculated from the anomalous specific heat. It increases from about 8% to about 55% of Rln2 with increasing x in the measured region. Very small values for small x in this region suggest the displacivelike character in the phase transition. And the order-disorder motion contributes more and more to the phase transition with increasing x. |
Rights: | © 2000 The American Physical Society |
Type: | article |
URI: | http://hdl.handle.net/2115/56815 |
Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 塩崎 洋一
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