Ferroaxial transitions in glaserite-type compounds; Database screening, phonon calculations, and experimental verification
山岸 茂直*; 林田 健志*; 三澤 龍介*; 木村 健太*; 萩原 雅人
; 村田 智城*; 廣瀬 左京*; 木村 剛*
Yamagishi, Shigetada*; Hayashida, Takeshi*; Misawa, Ryusuke*; Kimura, Kenta*; Hagihara, Masato; Murata, Tomoki*; Hirose, Sakyo*; Kimura, Tsuyoshi*
The so-called "ferroaxial transition" characterized by a rotational structural distortion that breaks a mirror symmetry has gained growing interest in terms of a new class of ferroic state in crystalline materials. RbFe(MoO
)
which belongs to glaserite-type compounds, $X□;1$$Y□;2$[
O
)
], is one of the most representative materials showing a ferroaxial transition, i.e., ferroaxial materials. Considering a variety of glaserite-type compounds, we expect that they provide a good arena for ferroaxial materials. In this work, we explored new ferroaxial materials by formula-based screening using regular expression search and symmetry detection algorithm. As a result, we found that a glaserite-type compound, K
Zr(PO
)
, is one of the promising candidates for ferroaxial materials. Experimentally, we demonstrate that K
Zr(P O
)
shows a ferroaxial transition at about 700 K, which is well explained by ab initio phonon calculations. The ferroaxial nature of K
Zr(PO
)
is further confirmed by the observation of its domain structures using a linear electrogyration effect, that is, optical rotation in proportion to an applied electric field. Our work provides an effective approach to exploring ferroaxial materials.