Bismuth-induced dielectric relaxation in the (1-x)La(Mg1/2Ti1/2)O3-xBi(Mg1/2Ti1/2)O3 perovskite system - Salak,AN; Ferreira,VM; Ribeiro,JL; Vieira,LG; Pullar,RC; Alford,NM (JOURNAL OF APPLIED PHYSICS, 2008)