Electrical and optical properties of dielectric BaTiO3 single crystals prepared by flux technique

Abstract EN

Single-crystal plates of BaTiO3 have been prepared for the first time by flux technique.

Both smooth and highly porous crystals were grown depending on growth temperature and rate of cooling.

Grown crystals contained an unidentified, low-symmetry barium titanate modification.

Annealing at 500-900 °C converted the crystals to the cubic phase, while annealing at 1000 °C produced the tetragonal phase and an increase in the grain size.

Grown and annealed crystals were highly dielectric with DC resistivity in the 1010-1012 Ω.cm range.

AC resistivity decreased with frequency following power-law dependence with an exponent of -0.6 to -0.7.

Both resistivity and capacitance remained stable at temperatures to 400 °C.

The effective dielectric constant (20-25 at 10 kHz) was possibly determined by amorphous grain-boundary region with high density of traps.