Nanoscale structure analysis of ferroelectric materials

Yoneda, Yasuhiro   ; Nam, H.*; Ueno, Shintaro*; Fujii, Ichiro*; Kim, S.*; Wada, Satoshi*

In nanoscale structural analysis of ferroelectrics by combining synchrotron radiation high-energy X-ray diffraction and pair distribution function (PDF) method, the deviation between the inside of the domain and the average structure can be extracted. The mixed crystal of BiFeO and BaTiO shows relatively good piezoelectric properties, but the properties are further improved by adding Bi(MgTi)O. When the experimentally obtained PDF was fitted with the cubic structure, which is the average structure, it could be reproduced almost completely in the region of 80 AA or more. However, in the region of 40 AA or less, the difference between the experimentally obtained PDF and the cubic structure is large, and it is clear that the local structure is different from the average structure. The ferroelectric mechanism can be clarified by structural modeling using the observed PDF brlowe 80 AA.