Enhancement microwave dielectric properties of La(Mg0.5Sn0.5)O3 ceramics by Substituting Mg2+ for Co2+

The microwave dielectric properties of La(Mg0.5−xCoxSn0.5)O3 ceramics were examined with a view to exploiting them for mobile communication. The La(Mg0.5−xCoxSn0.5)O3 ceramics were prepared using the conventional solid-state method with various sintering temperatures. The X-ray diffraction patterns of the La(Mg0.4Co0.1Sn0.5)O3 ceramics revealed that La(Mg0.4Co0.1Sn0.5)O3 is the main crystalline phase, which is accompanied by small extent of La2Sn2O7 as the second phase. Formation of this Sn-rich second phase was attributed to the loss of MgO upon ignition. Increasing the sintering temperatures seemed to promote the formation of La2Sn2O7. An apparent density of 6.67 g cm−3, a dielectric constant (ɛr) of 20.3, a quality factor (Q.F.) of 70,500 GHz, and a temperature coefficient of resonant frequency (τf) of −77 ppm °C−1 were obtained for La(Mg0.4Co0.1Sn0.5)O3 ceramics that were sintered at 1550 °C for 4 h.

► La(Mg0.4Co0.1Sn0.5)O3 ceramics sintered at 1550 °C for 4 h had a ɛr of 20.3.
► La(Mg0.4Co0.1Sn0.5)O3 ceramics sintered at 1550 °C for 4 h had a Q × f of 70,500 GHz.
► La(Mg0.4Co0.1Sn0.5)O3 ceramics sintered at 1550 °C for 4 h had a τf of −77 ppm °C−1.