Jilin Univ, Natl Lab Superhard Mat, Changchun 130023, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Lab Synchrotrol Radiat, Beijing 100039, Peoples R China
We study the energy-dispersive x-ray diffraction and Raman scattering of LiTaO3 at high pressure. The result remains stable up to 36 GPA. The average isothermal bulk modulus and its pressure derivative are obtained to be k(0) = (225 +/- 6) GPa and k'o = 1.3 +/- 0.5 at zero pressure by the Birch-Murnaghan equation of state and the "universal" equation of state. The linear incompressibility of LiTaO3 between the a- and c-directions differs by a factor of four, which shows that the compression is anisotropic.