DIELECTRIC-PROPERTIES OF (PB1-XXX)(ZR0.7TI0.3)O3 (X=CA, SR, BA) CERAMICS

The dielectric properties of (Pb1-xXx) (Zr0.7Ti0.3)O3 (X = Ca, Sr, Ba) ceramics (abbreviated PXZT) were investigated for applications to mul tilayer ceramic capacitors (MLCs) with dielectric layers thinner than 10 mum. The dissipation factors for MLCs with 5-mum-thick dielectric l ayers were estimated from those for 100-mum-thick disk specimens measu red at an oscillation voltage of 20 V(rms). Those for PCZT and PSZT we re less than 1.0% when the oscillation voltage was 20 V(rms), while th ose for conventional BaTiO3-based dielectric ceramics were greater tha n 2.5% at 20 V(rms). According to polarization-electric field hysteres is measurements, PCZT and PSZT revealed linear and double hysteresis l oops, respectively, while PBZT and BaTiO3 indicated typical ferroelect ric hysteresis loops. The differences in the dissipation factors for t he dielectric compositions are attributed to hysteresis in the polariz ation-electric field loops. These results suggest that PCZT and PSZT a re promising dielectric ceramics for MLCs with dielectric layers thinn er than 10 mum.