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This paper reports the observation of hexagonal phase of barium titanate by Mn doping and its effect on dielectric and magnetic properties. Ceramic samples of Ba 0.98 Zn 0.02 Ti 1− x Mn x O 3 (where, x = 0.04, 0.06 and 0.08) were prepared by traditional solid-state reaction route. The hexagonal phase is stabilized in the composition Ba 0.98 Zn 0.02 Ti 0.92 Mn 0.08 O 3 and a very feeble M – H loop is also observed in that composition. This induced magnetism is expected due to the exchange interactions between magnetic polarons formed by oxygen vacancies with Mn ions. The dielectric constant as well as the ferroelectric to paraelectric transition temperature is systematically decreased with increasing of Mn doping concentration. Further to that, the temperature dependent dielectric constant curve is also broadened at transition temperature with increasing of Mn concentration. However, the ferroelectric to paraelectric transition temperature is well above room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Our paper reports structural, magnetic and ferroelectric properties of Ni doped barium titanate. Ceramics samples of BaTi1−x Ni x O3 (here, x=0, 0.05, 0.1, and 0.15) were prepared through solid state sintering technique. It is revealed from structural studies that the phase transformation from tetragonal to hexagonal phase is strongly influenced by Ni doping concentration. Magnetism is induced in doped composition and the value of magnetism is dependent upon Ni ion concentration. This enhanced magnetic effect is likely to originate from carrier-mediated exchange interactions. Ferroelectricity was observed in all samples at room temperature, but it was decreased by Ni doping. [Copyright &y& Elsevier]

Abstract: This paper reports on multiferroic properties of Ho substituted BiFeO3 (Bi1−x Ho x FeO3) ceramics. It is observed that for x=0.15, a prominent ferroelectric loop is seen at 300K even if the system remains in rhombohedral (R3c) phase without appearance of any observable impurity phases. A well shaped M–H loop is observed at 10K for x=0.15. However it showed ferromagnetism, confirming the contribution of Ho3+ towards enhancement of ferromagnetic properties of BiFeO3 at 300K. Suppression of impurity phases of pure BiFeO3 bulk ceramic favors the reduction of mobile oxygen vacancies and reduces leakage current, due to which ferroelectric properties of BiFeO3 is enhanced. We argue that Ho substitution at Bi site is likely to suppress the spiral spin modulation and at the same time increase the canting angle, which favors enhanced multiferroic properties. XRD, SEM, magnetization, polarization and chemical bonding analysis measurements were carried out to explain the multiferroic behavior. [ABSTRACT FROM AUTHOR]