  The sol-gel prepared (1-x) Na0.5Bi0.5TiO3- (x) CaMnO3 (x=0, 0.03, 0.06, 0.12)
compositions show a Rhombohedral (R3c) phase for x=0.06 while a mixed
Rhombohedral (R3c) and orthorhombic (Pnma) phases for the x=0.12. The lattice
volume consistently decreased with an increase in the CaMnO3 content. The phase
transition temperature (Tc) decreased with an increase in the CaMnO3
compositions. The room temperature dielectric constant increased, and loss
decreased for the x=0.03 composition due to a decrease in the oxygen vacancy
and Bi loss confirmed by the valence state study (XPS). All the compositions
show a variation of the room temperature dielectric property with an
application of magnetic field confirming a magnetodielectric coupling. The
x=0.06 composition shows the highest negative magnetodielectric constant (MD%)
of 3.69 at 100kHz at an applied field of 5 kG.
