High-frequency electric modulus, impedance and conductance studies of gadolinium/niobium substituted barium titanate-lithium ferrite solids

Abstract

Using conventional solid-state techniques, BaTiO3- Li0.5Fe2.5O4composites doped with Gd/Nb are prepared. Investigations are made on the electric and micro-structural characteristics of composites at high frequencies. The tetragonal structure without phase change is confirmed by the composites BTO, BTOLF, BGN-1, and BGN-2. Using FESEM micrographs, the grain size of the composite samples BTO, BTOLF, BGN-1, and BGN-2 was determined. The Impedance (Z′), Complex Impedance (Z′′), and Mod of Impedance (|Z |) of all composites exhibit dispersion among the samples in the frequency range between 1 MHz and 1 GHz. The capacitance (C′) of BGN-2 falls between BTOLF and BGN-1 as a result of the effect of grain size.Due to the Gd/Nb doping in BTOLF, the true part of the composite's conductance (YS′) peak migrated towards lower and higher frequencies. All composites experience a rise in frequency beyond 1 GHz and a sharp peak in both the real component of the electric modulus (M') and the imaginary part of the electric modulus (M'').

Keywords

• BaTiO3
• FESEM
• Impedance
• Capacitance
• Electric modulus
• Composite