Structure,electric,and dielectric properties of(Sr_(0.7)Ca_(0.3))_(1.02)(Zr_(0.95−x)Ti_(0.05)Mn_(x))O_(3+δ)ceramics for BME-MLCCs application

Zirconate-based dielectric ceramics are potential materials for base metal electrode multilayer ceramic capacitors(BME-MLCCs)due to their exceptional chemical and thermal stability,as well as excellent dielectric properties.In this work,(Sr_(0.7)Ca_(0.3))1.02(Zr_(0.95−x)Ti_(0.05)Mn_(x))O_(3)+δ(SCZTM,0≤x≤0.05)ceramics with two coexisting phases were prepared using a solidstate reaction method in a reducing atmosphere.This study investigates the impact of Mn doping on sintering temperature,microstructure,and electrical properties of SCZTM ceramics.Mn doping can reduce the sintering temperature from 1450 to 1300℃.The impact of Mn doping on the structure and phonon vibration is minimal,resulting in a negligible effect on the intrinsic loss.The valence states of Mn ions and defects were characterized by X-ray photoelectron spectroscopy(XPS)and thermally stimulated depolarization current(TSDC)analysis.The results demonstrate the significant role of Mn doping in nonintrinsic loss.Due to the decrease in the concentration of oxygen vacancies(),SCZTM(x=0.01)ceramics exhibit attractive properties:resistivity(ρ)=8.93×10^(14)Ω·cm,dielectric constant(ε_(r))=36.16,dielectric loss(tanδ)=2.43×10^(–4),temperature dependence of dielectric constant(τ_(ε))=15.44 ppm/℃(@−55–200℃,1 MHz),Q×f=30,257 GHz(@6.12 GHz),and temperature coefficient of resonant frequency(τf)=–9.9 ppm/℃.SCZTM(x=0.01)ceramic powders were used to successfully fabricate Ni-based multilayer ceramic capacitors(MLCCs)with a high insulation resistance of IR≥39.6 TΩ,an ultralow dielectric loss of tanδ=0.2×10^(–4),and a wide operating temperature range(temperature coefficient of capacitance(T_(cc))=10.88 ppm/℃,@−55–200℃,1 MHz).SCZTM ceramics exhibit properties that make them suitable for use as BMEMLCC materials with potential market applications.