Microwave dielectric properties, chemical bonds and infrared reflection spectra of La2Sn2O7 ceramics with pyrochlore structures

The La2Sn2O7 ceramic was synthesized using the solid-phase reaction method. The crystal structure, sintering characteristics, and microwave dielectric properties of the La2Sn2O7 ceramics were studied. XRD analysis shows that La2Sn2O7 ceramics possess a pyrochlore structure with a space group of Fd3m. As the sintering temperature increases, the er and relative density show the same trend of change. The Qxf of ceramics has a strong correlation with the packing fraction. The P-V-L theory shows that La-O and Sn-O bonds have certain effects on the er and Qxf. The intrinsic dielectric properties of ceramics were analyzed using infrared reflection spectra. At 1350 degrees C, La2Sn2O7 ceramic obtained the largest relative density and optimum microwave dielectric properties (er = 15.65, Qxf = 73,804 GHz and tau f =-18.58 ppm/degrees C).