Year: 2012
Type: conference-paper
Abstract: Lattice vibrations of LaRu 2 Zn 20 , and LaIr 2 Zn 20 have been investigated by the local density approximation. Although these compounds have a cage structure in which a La atom is surrounded by Zn, the calculated results show that La vibrations have large dispersion and relatively high frequencies. In both compounds, it is found that the vibrations of Zn at 16c site in the plane perpendicular to the three-fold axis have very low frequencies and can be unstable. This result suggests that the transitions in LaRu 2 Zn 20 at 150 K and in LaIr 2 Zn 20 at 200 K are caused by these unstable modes.
Authors: Takumi Hasegawa, Norio Ogita, Masayuki Udagawa
Institution: Hiroshima University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W1998369364