Comment on "On the $T_S$-Anomaly in Betaine Calcium
B. Neubert and M. Pleimling
Recently, Hlinka and Ishibashi [J. Phys. Soc. Jpn. 67, 495 (1998)] discussed the
$T_S$-anomaly in betaine calcium chloride dihydrate (BCCD) in a Landau-type
approach. We comment on the shortcomings of this approach and discuss the
$T_S$-anomaly in the framework of a microscopical pseudo spin model based on a
realistic description of BCCD in terms of symmetry-adapted local modes.