|
|||||
|
|
Calorimetric and resistometric studies of La2CuO4+δ single crystals: Displasive character of phase transitions in 190–310 K |
|
| Affiliation: | a Research Laboratory of Engineering Materials, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 227, Japan * Department of Chemistry, Faculty of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152, Japan |
| Abstract: | Measurements of heat capacity, resistivity, and magnetic susceptibility for the La2CuO4+δ single crystals in the range 0.001≤δ≤0.035 revealed that following four kinds of phase transitions appear between 10 and 320 K: superconducting transition around 33 K, a transition around 200 K with small heat anomaly, martensitic transition around at 250–270 K, and a second order transition at 295 K. These transition temperatures strongly depended on the amount of excess oxygen content. The heat capacity anomalies for the sample with δ=0.035 in the range of 190 to 310 K were interpreted as connected with cooperative displacements of ions involving no diffusion process of oxygen ion. |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ | |