EXAFS STUDY ON THE LOCAL-STRUCTURE IN POTASSIUM TANTALATE

The local structure around Ta atom in potassium tantalate, KTaO3, has been investigated by using extended X-ray absorption fine structure (E XAFS) measurements. EXAFS spectra near the Ta-L(III) edge were observe d at temperatures from room temperature to 700 K. Anharmonicity of the thermal vibration delta((3)) in the Ta-O atomic pair, where these ato ms locate statistically on the inversion center, appears at high tempe ratures, while the delta((4)) is almost negligible below 700 K.