The magnetic properties of Bi 0.9Ba 0.1Fe 0.81M 0.09Ti 0.1O 3 solid solutions (M = Co, Mn, Sc, Al)

Abstract

Solid solutions with general formula Bi 0.9Ba 0.1Fe 0.81M 0.09Ti 0.1O 3 (M = Co, Mn, Sc, Al) together with parental Bi 0.9Ba 0.1Fe 0.9Ti 0.1O 3 were prepared by the traditional solid state reaction method. Their structural, room temperature magnetic, and dielectric properties were investigated. X-ray diffraction analysis indicated that all samples maintained original R3c space group. M– H hysteresis loop of Co 3+ doped sample saturated at an applied field of 1 T with spontaneous magnetization of 1.735 emu/g, while Mn 4+ substitution enhanced the magnetization of Bi 0.9Ba 0.1Fe 0.9Ti 0.1O 3 less strongly; addition of Sc 3+ helped decrease magnetic coercive field while Al 3+ modified sample exhibited paramagnetic M– H hysteresis loop. Differential scanning calorimetry was applied to determine the Neel temperature ( T N) and the T N for undoped, Co 3+, Mn 4+, Sc 3+, Al 3+ doped solid solutions were 318.1, 324.3, 335.7, 293.9 and 295.8 respectively. Sc 3+ substitution had little influence on the dielectric properties of Bi 0.9Ba 0.1Fe 0.9Ti 0.1O 3 while Al 3+ doping improved its dielectric constant. In contrast, Co 3+, Mn 4+ doped samples showed decreased permittivity but inhibited tan δ at frequencies larger than 30 kHz.