Microwave Characteristics of (Pb,Ca)(Fe,Nb,Sn)O 3 Dielectric Materials

The dielectric properties of (Pb 1− x Ca x ){(Fe 1/2 Nb 1/2 ) 1– y Sn y }O 3 solid solutions, where 0.4 lessthan equal tox ≤ 0.6, y = 0.05, 0.1, have been investigated at microwave frequencies. The replacement of Fe 3+ /Nb 5+ by Sn 4+ at the B–site of the perov‐skite structure considerably improves the loss quality factor Q and does not remarkably affect the dielectric constant epsilon r and the temperature coefficient of resonant frequency tau f . The tau f value of nearly 0 ppm/°C can be realized for x= 0.55. New high‐quality dielectric ceramics having epsilon r of 85.3‐89.9,Qf values of 7510‐8600 GHz, and τ f of 0‐9 ppm/°C were obtained at 1150°C for 3 h sintering in air. The influence of the sintering atmosphere on dielectric properties was also investigated.