Effects of Am~3+ Substitution on Dielectric Properties of Ca_1-xSm_2x/3TiO_3 Ceramics at Microwave Frequencies

摘要

Microwave dielectric properties of Ca_1-xSm_2x/3TiO_3 ceram- ics were investigated as a function of the amount of Sm~3+ substitution (0.0≤x≤0.8). The structure was changed from orthorhombic perovskite at x=0.0 to tetragonal at x=0.6. As the calcium vacancy concentration increased with in- Creased Sm~3+ substitution, the unloaded Q value (≈1/tan δ) Increased up to the solid-solution limit at x=0.6 and then Decreased because of formation of the secondary phase Sm_2Ti_2O_7.