Phase Ratio, Dielectric, Ferroelectric, and Magnetic Properties of BCTZ Ceramics with CuO Doping Synthesized by the Solid State Combustion Technique

Abstract

This work investigates the effect of CuO doping (0-1.0 wt%) on the phase formation, microstructure, electric, and magnetic properties of (Ba 0.85 Ca 0.15 ) (Ti 0.90 Zr 0.10 )O 3 (BCTZ) ceramics. These samples are fabricated by the solid state combustion technique using glycine as fuel. The powders and ceramics are calcined and sintered at 1050 and 1450 C, respectively, for 2 h. The coexistence of the orthorhombic and tetragonal phases is observed in all samples. Increasing the amount of CuO doping enhances orthorhombicity, as verified by the Rietveld refinement technique. The orthorhombic and tetragonal phases are close to equal in the 0.4 wt% CuO doped sample. The grain size continuously increases as more CuO is added up to 0.4 wt% and then the size decreases due to the accumulation of excessive CuO at the grain boundaries. The density, dielectric constant, and ferroelectric properties tend to be enhanced when the CuO doping increase from 0 to 0.4 wt%, then they start to degrade. By increasing the CuO concentration from 0 to 0.8 wt%, the ceramics exhibit diamagnetic behavior. A ferromagnetic hysteresis loop is observed in the ceramic with 1.0 wt% CuO doping when measured at a temperature of 50 K.