Microwave dielectric properties of new SrLa4-xNdxTi5O17 ceramics

New microwave dielectric ceramics in the SrLa4-xNdxTi5O17 (0 <= x <= 4) composition series were prepared through a solid state mixed oxide route. All the compositions formed highly dense (similar to 95%) single phase ceramics upon sintering at 1500-1580 degrees C. The molar volume and theoretical density decreased due to the substitution of small (1.27 angstrom) Nd ions for large (1.36 angstrom) La ions. This decrease was associated with a decrease in the dielectric constant (epsilon(r)), temperature coefficient of resonant frequency (tau(f)) and quality factor (Q(u),f(o)). An analysis of properties achieved in the present study indicated that ceramics exhibiting nearly zero tau(f) corresponding to epsilon(r) similar to 54 could be fabricated in the SrLa4-xNdxTi5O17 composition series at x similar to 1.6; however, further work is required to improve Q(u)f(o)(similar to 6000 GHz) for possible practical applications. (C) 2011 Elsevier Ltd. All rights reserved.