The influence of La3+ and Nd3+ substitution for the Bi3+ cations in the low-firing Bi2Mo2O 9 system is considered in regard to the sintering behavior, density, phase composition, and microwave dielectric properties. All the compositions can be sintered to high densities in temperature range of 620°-680°C. In (Bi1-xLnx)2Mo2O9 (Ln=La, Nd) ceramics, when x≤0.2 the solid solution is within a monoclinic phase (P21/n) and the phase had an increase in melting temperature with the doping. In the La substitution case, the (Bi0.8La0.2) 2Mo2O9 ceramics had the best microwave dielectric properties with a permittivity of 32.7, a Qf value (f=resonant frequency, Q=1/dielectric loss at f) of 13 490 GHz and a temperature coefficient of -4.6 ppm/°C. With the Nd-substituted samples, the (Bi0.9 Nd0.1) 2Mo2 O9 ceramics had the best microwave dielectric properties with a permittivity of 33.9, a Qf value of 15 200 GHz and a temperature coefficient of +8.05 ppm/°C. The substitution of La and Nd can effectively modify the microwave dielectric properties of Bi 2Mo2O9 ceramic and in particular adjust the temperature coefficient to near zero. The (Bi1-xLnx) 2Mo2O9 (Ln=La, Nd) ceramics are very interesting new materials for an ultralow-temperature cofired ceramics technology that is compatible with Al metal electrodes.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry