Structure, Microwave Dielectric Properties, and Novel Low-Temperature Sintering of m>xm>SrTiO3-(1−m>xm>)LaAlO3 Ceramics with LTCC Application
文摘
m>xm>SrTiO3–(1−m>xm>)LaAlO3 ceramics with ZnO–B2O3 sintering aid were prepared by solid-state reaction method leading to a significant decrease in sintering temperature from 1550°C to 1050°C. The structure, microwave dielectric properties, and low-temperature sintering behavior were systematically investigated. The results revealed the relationships among ionic size, ionic polarizability and cell volume. With increasing additive, chemical ordering of B-site cations was indicated with selected area electron diffraction (SAED) patterns, HRTEM images and Raman spectrum, which contributed to the greatly enhanced microwave dielectric properties. Particularly, the 0.7Sr0.85 Mg0.15TiO3–0.3LaAlO3 ceramics modified with 10 wt % ZnO-B2O3 can further decrease the sintering temperature down to 950°C without deteriorating its performance. Thermal tests implied ceramics featured good chemical compatibility with Cu/Ag electrode. Thus, they can be cofired with internal Cu/Ag electrodes in special patterns to fulfill different electrical functions for LTCC (low-temperature cofired ceramic) application.