Pressure-Induced Phase Transition in BaTiO3 Nanocrystals
LI Feng-Ying1, JIN Chang-Qing1, YOU Shu-Jie1, XIAO Chang-Jiang1, YU Ri-Cheng1, WANG Xiao-Hui2, LIU Jing3, LI Xiao-Dong3, LI Yan-Chun3, CHEN Liang-Chen1
1Institute of Physics, Chinese Academy of Sciences, Beijing 100080
2Department of Materials, Tsinghua University, Beijing 100084
3Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039
Pressure-Induced Phase Transition in BaTiO3 Nanocrystals
1Institute of Physics, Chinese Academy of Sciences, Beijing 100080
2Department of Materials, Tsinghua University, Beijing 100084
3Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039
Abstract： The crystal structure and electric properties of BaTiO3 nanocrystals are studied by in situ high-pressure synchrotron radiation x-ray powder diffraction. The phase transition takes place not only in the samples of BaTiO3 nanocrystals that are tetragonal phase with grain sizes more than 100nm, but also in the samples of BaTiO3 nanocrystals that are cubic phase with grain sizes less than 100nm. The pressures of phase transition are found to increase with decrease of the grain size from about 4 to 10GPa for crystallites ranging from 200 to 10nm in radius. The bulk moduli are calculated according to Birch--Murnaghan state equation before and after the phase transition.
2006, Vol. 23 
