We have investigated multiple caloric effects in multiferroic Y2CoMnO6. Polycrystalline sample prepared by solid state method has shown a ferromagnetic Curie temperature 75 K with second order phase transition; a maximum magneto entropy change -$Delt
a$S_{Mmax}) of ~ 7.3 J/kg K with reasonable relative cooling power 220 J/kg is found without thermal and magnetic hysteresis loss. Electric field driven entropy change (-$Delta$S_{Emax}) of ~ 0.26 J/m^3 K obtained using the Maxwells relation and estimated magnetically induced total temperature change of 5.45 K around Curie temperature that confirms the multicaloric effect in the sample.
We present sharp magnetization jumps and field induced irreversibility in magnetization in multiferroic Y2CoMnO6. Appearance of magnetic relaxation and field sweep rate dependence of magnetization jumps resemble the martensite like scenario and sugge
sts the coexistence of E*-type antiferromagnetic and ferromagnetic phases at low temperatures. In Y2CoMnO6, the critical field required for the sharp jump can be increased or decreased depening 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 field cooling. The cooling field dependence on the sharp magnetization jumps has been described by considering exchange pinning mechanism at the interface, like in exchange bias model.
We report a giant zero field cooled exchange bias (ZEB) effect (~0.65 T) in La1.5Sr0.5CoMnO6 sample. Magnetic study has revealed a reentrant spin glass ~90 K, phase separation to spin glass and ferromagnetic phases below 50 K and canted antiferromagn
etic transition ~10 K. A small conventional exchange bias (CEB) is established with the advent of spontaneous phase separation down to 10 K. Giant ZEB and enhanced CEB effects are found only below 10 K and are attributed to the large unidirectional anisotropy at the interface of isothermally field induced ferromagnetic phase and canted antiferromagnetic background.
