Crystallographical and morphological changes in charge-ordering transition of RFeO (R: Y, Lu) investigated by transmission electron microscopy

Horibe, Yoichi*; Mori, Shigeo*; Ikeda, Naoshi*; Yoshii, Kenji; Maeno, Hiroshi*; Murakami, Yasukazu*

Ferroelectrics, 584(1), p.20 - 30, 2021/00

https://doi.org/10.1080/00150193.2021.1984762

Temperature dependence of charge-ordered crystal structures and domain structures in RFeO (R: Y and Lu) was investigated by energy-filtered transmission electron microscopy, combined with conventional transmission electron microscopy. The presence of three-dimensional to two-dimensional charge ordering transition were observed in both RFeO on heating. Furthermore, real-space images obtained with the energy-filtered transmission electron microscopy revealed that YRFeO has less anisotropic nanometer-scale charge-ordered domains than LuRFeO. These findings in RFeO indicate the importance of the interchange interactions between Fe-O bilayers in addition to those within bilayers in the structural phase transitions associated with charge ordering in this system.