A Study of quantum effects on atom displacements in quartz

Hayashi, Makoto*; Kanai, Takashi*; Yamada, Takahiro*; Fujishita, Hideshi*; Igawa, Naoki   ; Kihara, Kuniaki*

While the temperature change of the static order paramaters, such as an atom displacement and lattice destortion around the phase transition temperature is exlained by the classical Landau theory, the tempereture dependence of those parameters below the transition temperature was predicted by Salje. In this report, temperature dependence of strucural parameters of quartz was measured using the nuetron powder diffraction and analyzed by the Rietveld method to confirm the theory predicted by Salje. The quantitative analysis of present works gave a good agreement with the theory.