Modification of spinel system Mg2TiO4 with Al3+ and Ca2+ substitution

Microwave Dielectrics (MD) are the special class of ceramics which have very low dissipation factor and very low temperature co-efficient of dielectric constant and very high densification (> 95%). Microwave Dielectric materials are used as the basis for resonators and filters for the microwave carrying the desired information. For achieving the high speed, miniature size components, higher value dielectric materials with very high quality factor which are temperature stable is required. Magnesium and titanium based compounds such as MgTiO3 and Mg2TiO4 are widely used as microwave dielectric based devices because of their stable nature at microwave frequencies. In the present work the effect of Al3+ and Ca2+ substitution on the dielectric properties (epsilon' and Q factor) of the microwave dielectric material- MgTi2O4 is studied. The structural, microstructural and dielectric properties in the high frequency and low frequency region are studied. The temperature variation of the dielectric constant in the low frequency shows the temperature stability of the ceramics prepared. In all the samples studied dielectric tangent loss is of the order of 10(-4) range. FESEM studies showed the densely packed grains for all the ceramics (grain size ranging from 5 mu m-10 mu m).