Metamagnetic behaviour and effect of field cooling on sharp magnetization jumps in multiferroic Y sub(2)CoMnO sub(6)

We present sharp magnetization jumps and field-induced irreversibility in magnetization in multiferroic Y sub(2)CoMnO sub(6). The appearance of magnetic relaxation and field sweep rate dependence of magnetization jumps resembles the martensite-like scenario and suggests the coexistence of E*-type antiferromagnetic and ferromagnetic phases at low temperatures. In Y sub(2)CoMnO sub(6), the critical field required for the sharp jump can be increased or decreased depending on the magnitude and direction of the cooling field; this is remarkably different from manganites or other metamagnetic materials where the critical field increases irrespective of the direction of the applied field cooling. The cooling field dependence on the sharp magnetization jumps has been described by considering exchange pinning mechanism at the interface, like in the exchange bias model.