Dielectric and X-ray Diffraction Analysis of Ba(Ga,Ta)_0.05Ti_0.90O₃

Abstract

Ba(Ga,Ta)_0.05Ti_0.90O₃, a B-site dipole-like substituted material is investigated for structural phase transitions over the temperature range 30 to 900°C using x-ray diffraction. Rietveld refinement of the data suggests the material to be Pmm (cubic) from 200 to 900°C, P4/mmm (tetragonal) from 30 to 200°C with phases similar to those of BaTiO₃ [12]. Average grain size determined using scanning electron microscopy is 650 nm. Measurements of dielectric properties from −50 to 120°C and over a frequency range of 10 Hz to 2 MHz show a relatively flat dielectric constant that is electric-field tunable indicating that Ba(Ga,Ta)_0.05Ti_0.90O₃ is a reasonable candidate for frequency agile components.

Keywords:

• Barium titanate
• BaTiO₃
• dielectric
• X-ray diffraction
• SEM
• dopant
• substitution
• dipole-like
• Rietveld refinement