Low temperauture XRD analysis of BaTiO3

Design, Rigaku corporation
â—‹koichi Ishibashi kazuyosi arai ryuji matsuo katsuhiko inaba

Baruim Titanate (BaTiO3) is one of the functional oxide materials with a Perovskite-type structure, and used in various industrial applications, such as piezoelectric actuators, ferroelectric random access memories, so on. Successive structural phase transitions have been reported, resulting from a slight shift of cationic position in oxygen-surrounding polyhedra with varying temperature. Though tremendous studies are conducted focusing on phase transitions at high temperature between the paraelectric phase and the ferroelectric phase, its behaviour at low temperature has not been fully understood.
We have developed a new X-Ray Diffraction analysis system(SmartLab RIGAKU Co.) with a low temperature chamber, which will be applicable to XRD measurement both for powder specimen and for films on substrates.
A specially-designed hemispherical-domed X-ray window covering a sample chamber with heating/cooling system enables XRD measurements for films along the directions of stacking sequences (Out-of-Plane direction) and also along the directions within the surface planes (In-Plane direction). Together with this configuration of sample chamber and the specially designed goniometer system with horizontal sample mounting both for Out-of-Plane and In-Plane XRD measurement, anisotropic bahaviour of lattice expansion/compression of films on substrates will be easily analyzed.
We will report results of XRD analyses at low-temperature for BaTiO3 samples comparing powder specimen and BaTiO3 films on substrates.