Structure, Dielectric Properties, and Applications of CaTiO ₃ ‐Modified Ca ₄ MgNb ₂ TiO ₁₂ Ceramics at Microwave Frequency

Abstract

High‐dielectric‐constant and low‐loss ceramics in the (1− x )Ca 4 MgNb 2 TiO 12 – x CaTiO 3 system have been prepared by the conventional solid‐state route. The forming of complete (1− x )Ca 4 MgNb 2 TiO 12 – x CaTiO 3 solid solutions were confirmed by the X‐ray diffraction pattern analysis and the measured lattice parameters, which linearly varied from a =5.5478 Å, b =7.7710 Å, and c =5.4543 Å for x =0.1 to a =5.4718 Å, b =7.6799 Å, and c =5.4262 Å for x =0.9. By increasing x , not only could the τ f of the ceramics be turned to a near‐zero value (∼−6.9 ppm/°C) at x =0.3, a substantial Q × f (∼20 200 GHz) and ɛ r (∼43.88) could also be achieved simultaneously.