Nonstoichiometry and thermal expansion of SnTe
- 作者：O.N. Nashchekina ; E.I. Rogacheva ; V.P. Popov
- 关键词：A. Chalcogenides ; D. Defects ; D. Phase transitions ; D. Lattice dynamics ; D. Thermal expansion
- 刊名：Journal of Physics and Chemistry of Solids
- 出版年：2008
- 期刊代码：69_00223697
- 类别：ch
- 出版时间：February-March 2008
- 卷：69
- 期：2-3
- 页码：273-277
- 文件大小：154 K
摘要
The influence of kinetic factors on dependences of thermal expansion coefficient (<i>αi>) of SnTe crystals on temperature and deviation from stoichiometry was studied. The <i>αi>(<i>Ti>) dependences were obtained under stationary and dynamic (without keeping samples for a long time at fixed temperatures) regimes. In the case of a stationary regime, an increase in <i>αi> with increasing temperature (4.2–300 K) was registered, and anomalies in <i>αi>(<i>Ti>) dependences were observed and attributed to phase transitions. In the case of a dynamic regime, <i>αi>(<i>Ti>) dependences exhibited an oscillatory behavior, most pronounced in the sample with 50.4 at%Te. It is suggested that the observed behavior of <i>αi>(<i>Ti>) dependences is connected with an oscillatory process of approaching the equilibrium in the intrinsic defect subsystem and with simultaneous occurrence of relaxation processes and temperature-phase transitions. It was established that regardless of the measurement regime, a minimum in the <i>αi> isotherms is observed at <img src="http://www.sciencedirect.com/scidirimg/entities/223c.gif" alt="not, vert, similar" border=0>50.4 at%Te.