Analysis of lattice vibration in fine particles of barium titanate single crystal including the lattice hydroxyl group

Abstract

Fine particles of barium titanate single crystal with an average particle size of about 66 nm were prepared by a hydrothermal method. In the as-prepared sample, there was a large amount of the hydroxyl group and barium vacancy, and its crystal structure was assigned to cubic with an expanded lattice using a Rietveld method. The hydroxyl group desorbed with increasing calcination temperature, especially desorbing remarkably in the range from 200 to 300 °C. Above 700 °C, there was no hydroxyl group in the particle, and the crystal structure of the sample treated at 800 °C was assigned to tetragonal with tetragonality of 1.001 using a Rietveld method. The state of the lattice vibration was measured by an infrared reflection method, and analyzed using a nonlinear least-squares method with a four-parameter semiquantum model. As the result, the crystal structure of the as-prepared sample estimated using Fourier transform infrared and Raman was assigned to tetragonal. On the O6 octahedra deformation mode, the resonance frequency was independent of the concentration of the lattice hydroxyl group while the damping factor decreased with decreasing concentration of the lattice hydroxyl group. The role of the lattice hydroxyl group on the O6 octahedra deformation mode is discussed.

Investigation of the hydrothermal crystallisation of the perovskite solid solution NaCe1−La Ti2O6 and its defect chemistry

“…This band was not observed in sintered NaLaTi 2 O 6 confirming that all the O-H containing species are removed upon heating (note that sintering NaCeTi 2 O 6 causes phase separation so IR of that sample was not recorded). Similar results are reported in the literature for perovskites prepared hydrothermally [58,68,70,71]. Noma et al observed a sharp band at around 3500 cm -1 in hydrothermal BaTiO 3 , which they attributed to lattice hydroxyl groups occupying the oxide sites, and a broad band from 3000-3600 cm -1 which was ascribed to surface-adsorbed hydroxyl groups, present either as hydroxide or as water.…”

Synthesis and Structural Characterization of Nanocrystalline Batio3 at Various Calcination Temperatures

“…For the synthesis of a pure, homogeneous and nanometric level of BTO, wet chemical routes have been used, which have huge economic advantages over the conventional manufacturing methods (solid-solid reaction) [7][8][9]. As an alternative, Raman spectroscopy is a powerful experimental tool for studying the lattice vibrations and other elementary excitations in materials, providing important information about the structure, composition, strain, defects, and phase transitions.…”

EFFECT OF MILLING TIME ON PHASE TRANSITION IN BaTi0.095W0.05O3 NANOCERAMICS SYNTHESIZED BY HIGH-ENERGY BALL MILLING

“…The value of remnant polarization is increased with increasing milling duration. The value of remnant polarization is much higher as compared to that obtained from solid -state reaction method`2 7 . Piezoelectric coefficients of the studied samples is shown in Table 1.…”

“…BaTiO 3 nanocrystals have been synthesized by various techniques like hydrothermal method 6,7 , sol-gel processing 8 oxalate route 9 and polymeric precursor methods 10 . Although BaTiO 3 nanoparticles produced by these methods are smaller than 100 nm, they contain residual hydroxide ions 11,12 .…”