Dielectric properties of Mg- and Mn-doped (Ba1−xSrx)(Ti1−yZry)O3

Abstract

This study showed that the substitution of SrO and ZrO2 in BaTiO3 results in a change in the unit cell volume, Curie temperature shift and temperature dependence of dielectric constants. The unit cell volume decreased with an increasing SrO content (≤15 mol%), but increased with an increasing ZrO2 (≤10 mol%). Substitution of Zr4+ ions for Ti sites in Ba(Ti1−yZry)O3 shifted the Curie point (Tc) to lower temperatures by 4.1 °C per mol% of ZrO2 at y≤0.10. SrO substitution in the samples with 10 mol% ZrO2 (Ba1−xSrx)(Ti0.9Zr0.1)O3 brought about relatively small shifts in Tc (2.2 °C/mol%), and their dielectric constants decreased with an increasing SrO content near Tc. Mg- and Mn-doped (Ba0.9Sr0.1)(Ti0.9Zr0.1)O3 broadened the dielectric constant peaks at Tc with uniform microstructures, which satisfies the temperature characteristics of Y5V specifications. The leakage currents of the Mg- and Mn-doped samples were significantly suppressed.