Structure of sol-gel prepared ferroelectric Bi3.4La0.6Ti3O12

Abstract

The Bi3.4La0.6Ti3O12 (BLT) thin film and powder have been prepared by a sol-gel method with annealing at 700 degrees C. Randomly oriented BLT thin film exhibits a large remanent polarization, 2P(r) = 72 mu C/cm(2), with a dc applied field strength of 320 kV/cm. Structure of sol-gel derived BLT powder has been investigated by neutron scatterings, and refined by a Rietveld method resulting a reasonable goodness of fit (wR(p) = 6.7%, and R-p = 5.7%) using an orthorhombic (B2cb, a = 5.4221 angstrom, b = 5.4032 angstrom, and c = 32.8361 angstrom). Two different TiO6 octahedra exhibit different polarization directions; (100) from Ti(1)O-6, and (011) from Ti(2)O-6, which explains the observed large 2P(r) of the randomly oriented BLT thin film.