Effect of holmium substitution for the improvement of multiferroic properties of BiFeO₃

This paper reports on multiferroic properties of Ho substituted BiFeO ₃ (Bi_1-xHo_xFeO₃) ceramics. It is observed that for x=0.15, a prominent ferroelectric loop is seen at 300 K even if the system remains in rhombohedral (R3c) phase without appearance of any observable impurity phases. A well shaped MH loop is observed at 10 K for x=0.15. However it showed ferromagnetism, confirming the contribution of Ho ³⁺ towards enhancement of ferromagnetic properties of BiFeO ₃ at 300 K. 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.