Effects of La2O3/ZnO Additives on Microstructure And Microwave Dielectric Properties of Zr0.8Sn0.2TiO4 Ceramics


  • V. R. W. Amarakoon—contributing editor

  • Presented at the 93rd Annual Meeting of the American Ceramic Society, Cincinnati, OH, May 1,1991 (Electronic Division, Paper No. 108-E-91).

  • Based on the thesis submitted by R. Kudesia for the Ph.D. degree in ceramics, Alfred University, Alfred, NY, 1992.

  • Supported by the Center of Advanced Ceramic Technology at the New York State College of Ceramics.

  • McHale Consulting, 1532 Moland Rd., Alfred Station, NY 14803.


Dielectric ceramics of Zr0.8Sn0.2TiO4 containing La2O3 and ZnO as sintering aids were prepared and investigated for microstructure and microwave dielectric properties. Low-level doping with La2O3 and ZnO (up to 0.30 wt%) is good for densification and dielectric properties. These additives do not affect the dielectric constant and the temperature coefficient. Dielectric losses increase significantly at additive levels higher than 0.15 wt%. The combined additives La2O3 and ZnO act as grain growth enhancers. With 0.15 wt% additives, a ceramic having a dielectric constant, a quality factor, and a temperature coefficient of frequency at 4.2 GHz of 37.6, 12 800, and –2.9 ppm/°C, respectively, was obtained. The quality factor was considerably improved by prolonged sintering.