Study of exchange bias and training effect in NiCr2O4

• For the first time, we are reporting the exchange bias behavior of NiCr2O4..
• Presence of both ferri-/anti-ferromagnetic components gives rise to exchange bias.
• The exchange bias field is found to decay exponentially as temperature increases.
• Coercive field follows the function, Hceff=HCeff (0)[1-(T/T′C)2].

Single phase sample of NiCr2O4 crystallized in a tetragonal structure of I41/amd space group was prepared. Ferrimagnetic transition at TC=73 K along with a large irreversibility has been observed from the magnetization measurement. The sample exhibits exchange bias phenomenon and it is explained by considering the anisotropic exchange interaction between the ferrimagnetic and the antiferromagnetic components of magnetic moment. Presence of training effect is also observed. The exchange bias field (HEB) is found to decay exponentially with increase in temperature and however, the coercive field (HCeff) follows the empirical relation HCeff=HCeff01−TTC'2. The maximum experimental values of HEB and HCeff are found to be 313 Oe and 4839 Oe respectively.