화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.103, No.12, 6811-6821, 2020
Ultralow dielectric loss in Y-doped SrTiO(3)colossal permittivity ceramics via designing defect chemistry
Effects of doping of Y and sintering atmosphere on the dielectric properties of Sr(1-1.5)(x)Y(x)TiO(3)ceramics (SYT,x = 0-0.014) were systematically investigated. The SYT14 (x = 0.014) ceramic sintered in N(2)attains a colossal permittivity (CP, & x190;(r) = 28 084@ 1kHz, 27 685@ 2MHz) and an ultralow dielectric loss (tan delta = 0.007@ 1kHz, 0.003@ 2MHz) at room temperature. Because of using of the A-site deficient, there areVSr,,in SYT ceramics. Through the comprehensive analysis of dielectric responses, X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and complex impedance data, it is proved that doping of Y promotes the formation ofYSr center dot(Y(3+)are located at Sr(2+)site),YTi,(Y(3+)are located at Ti(4+)site), and Ti3+, and sintering in reducing atmosphere of N(2)results in moreVO center dot center dot(oxygen vacancy) andVSr,,(strontium vacancy) generating in SYT ceramics. The defect dipoles,suchasVSr,,-VO center dot center dot,Ti4+center dot e-VO center dot center dot-e center dot Ti4+,YSr center dot-e center dot Ti4+,2YSr center dot-VSr,,,YSr center dot-YTi,, and2YTi,-VO center dot center dot formed by introduced defects make charge carriers localized in SYT ceramics. The combined action of the massive defect dipoles is responsible for the ultralow tan delta and CP in SYT14 ceramics sintered in N-2.