Oxygen-deficient effect on charge ordering in spin- and charge-frustrated ferrite YFeO

Horibe, Yoichi*; Yoshii, Kenji  ; Ikeda, Naoshi*; Mori, Shigeo*

The effects of oxygen deficiency on charge ordering were investigated by transmission electron microscopy at various deficiencies and temperatures of YFeO. We found that the detailed nature of the charge ordering structures is associated with changes in the superlattice reflections and diffuse scattering. They go from (1/3 1/3 1/2)-type superlattice reflection to (1/3 1/3 )-type straight-type diffuse scattering, then to zigzag-type diffuse scattering. With the oxygen deficiencies increased, the interchange correlation of Fe-O bilayers obviously decreases, yet the triple super periodicity along [110] remains unchanged. These findings on frustrated ferritesindicate the stability of in-plane threefold charge ordering and the importance of the interchange interaction between bilayers in the structural phase transitions.