Single Crystal Growth with Flux Method and Local Structure Analysis around Fe Using X-ray Fluorescence Holography for Multiferroic Pb(Fe_1/2Ta_1/2)O₃

抄録

Lead iron tantalate (PFT) is multiferroic material and has a complex perovskite structure. To analyze the local structure, we grew a PFT single crystal and applied X-ray fluorescence holography to the grown single crystal. We analyzed the temperature dependence of the first neighbor Pb atomic image around Fe and found that the atomic image intensity almost monotonically increased with decreasing temperature. This behavior is in marked contrast to the case of lead iron niobate, where the Pb atomic image intensity shows an abrupt decrease by cooling down below the magnetic transition temperature of about 150 K. This finding is discussed in relation to the energy gain of Ta and Nb due to the second order Jahn-Teller effect.