High dielectric permittivity in AFe1/2B1/2O3 nonferroelectric perovskite ceramics (A=Ba, Sr, Ca; B=Nb, Ta, Sb)

AFe 1/2 B 1/2 O 3 (A=Ba , Sr, Ca; B=Nb, Ta, Sb) ceramics were synthesized and temperature dependences of dielectric permittivity were measured at different frequencies. The experimental data obtained show very high values of dielectric permittivity in a wide temperature interval that is inherent to so-called high-k materials. Analyses of these data establish a Maxwell–Wagner mechanism as a main source for the phenomenon observed.