Structure and microwave dielectric properties of double vanadate Ca 9 A(VO 4 ) 7 (A= La, Pr, Nd and Sm) ceramics for LTCC applications

Ca 9 A(VO 4 ) 7 (A = La, Pr, Nd and Sm) ceramics have been prepared by conventional solid state ceramic route. The phase purity of the samples was confirmed by powder X-ray diffraction technique. Raman spectroscopic studies confirm the existence of (VO 4 ) 3− vibrational groups in Ca 9 A(VO 4 ) 7 ceramics. Ca 9 A(VO 4 ) 7 (A = La, Pr, Nd and Sm) ceramics exhibit microwave dielectric properties of ε r = 9.8 to 10.4, Qxf = 4500 to 14,900 GHz and low temperature coefficient of resonant frequency τ f = −3.8 to −10.2 ppm/°C. Ca 9 A(VO 4 ) 7 ceramics with A = La, Nd and Sm show good chemical compatibility with Ag electrode and can be used as candidate materials for LTCC applications.