Affiliation:
1. Institute of Laser Engineering, Beijing University of Technology, Beijing, 100124, P. R. China
Abstract
Spontaneous polarization was found in Ta2O5 dielectric ceramics prepared by laser sintering technique. After heat corrosion, 90° and 180° domains in the ceramics was observed by field emission scanning electron micrographs. The crystal structure of the laser-sintered ceramics at RT was determined as monoclinic phase, which indicates the lattice distortion existed in the ceramics. The variation of O-Ta-O bending vibration mode was deduced from the variation of phonon mode at the low wave-number (57 cm-1 and 250 cm-1). The enhancement of effective electric field for tantalum atoms due to the lattice distortion was determined by calculation of charge distribution coefficients. The distortion of crystal structure due to the phase transformation from higher symmetric orthorhombic phase to lower symmetric monoclinic phase explained spontaneous polarization in the laser-sintered Ta2O5 ceramics.
Publisher
World Scientific Pub Co Pte Lt
Subject
Electrical and Electronic Engineering,Condensed Matter Physics,Ceramics and Composites,Electronic, Optical and Magnetic Materials