Ac susceptibility studies of multiferroic BiMnO3 and solid solutions between BiMnO3 and BiScO3

The real and imaginary parts of the ac susceptibilities of powder BiMnO(3) and BiMn(1-x)ScxO(3) (x = 0.1, 0.2, 0.3, 0.4, 0.5, and 0.7) samples have been measured as functions of temperature, different driving ac and applied dc magnetic fields, and different ac magnetic field frequencies. Both. chi' versus T and. chi'' versus T showed strong dependence on the parameters of the ac magnetic field for ferromagnetic samples BiMnO(3) and BiMn(1-x)ScxO(3) (x = 0.1, 0.2, and 0.3), indicating that the ac field interacted mainly with the domain structure. In BiMn(1-x)ScxO(3) (x = 0.1, 0.2, and 0.3), a re-entrant spin-glass transition emerged at low temperatures. The re-entrant spin-glass transition temperature T(RSG) increased with increasing x (T(RSG) = 4 K for x = 0.1, T(RSG) = 5 K for x = 0.2, and T(RSG) = 9 K for x = 0.3). For BiMn(1-x)ScxO(3) (x = 0.4, 0.5, and 0.7), only the classical spin-glass transition was found (the freezing temperature T(f) = 24 K for x = 0.4, T(f) = 18 K for x = 0.5, and T(f) = 7 K for x = 0.7) with characteristic frequency dependence of broad maxima on the. chi' versus T and. chi'' versus T curves and no dependence on the driving ac field.