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Electric field controlled magnetic exchange bias and magnetic state switching at room temperature in Ga doped {\alpha}-Fe2O3 oxide

Research paper by R. N. Bhowmik, Abdul Gaffar Lone

Indexed on: 13 Jul '17Published on: 13 Jul '17Published in: arXiv - Physics - Materials Science



Abstract

We have developed a new magnetoelectric material based on Ga doped {\alpha}-Fe2O3 in rhombohedral phase. The material is a canted ferromagnet at room temperature and showing magneto-electric properties. The experimental results of electric field controlled magnetic state provided a direct evidence of room temperature magnetoelectric coupling in Ga doped {\alpha}-Fe2O3 system. Interestingly, (un-doped) {\alpha}-Fe2O3 system does not exhibit any electric field controlled magnetic exchange bias shift, but Ga doped {\alpha}-Fe2O3 system has shown an extremely high electric field induced magnetic exchange bias shift up to the value of 1120 Oe (positive). On the other hand, in a first time, we report the electric field controlled magnetic state switching both in {\alpha}-Fe2O3 and in Ga doped {\alpha}-Fe2O3 systems. The switching of magnetic state is highly sensitive to ON and OFF modes, as well as to the change of polarity of applied electric voltage during in-field magnetic relaxation experiments. The switching of magnetic state to upper level for positive electric field and to down level for negative electric field indicates that electric and magnetic orders are coupled in the Ga doped hematite system. Such material is of increasing demand in today for multifunctional applications in next generation magnetic sensor, switching, non-volatile memory and spintronic devices.