Double glassy states and large spontaneous and conventional exchange bias in La1.5Ca0.5CoFeO6ferrimagnetic double perovskite.

ABSTRACT

The structural and magnetic properties of hole doped double perovskite La1.5Ca0.5CoFeO6have been investigated by measuring x-ray photoemission spectroscopy, neutron powder diffraction and magnetization. A ferrimagnetic transition is observed atTC∼ 167 K. The presence of anti-site disorder (ASD) in La1.5Ca0.5CoFeO6has also been demonstrated. Double re-entrant cluster glass transitions (T1∼ 11 K andTS∼ 35 K) were observed which has been attributed to the ASD effect. The presence of both large spontaneous exchange biasHSEB∼ 2.106 kOe and giant conventional exchange biasHCEB∼ 1.56 T at 5 K has also been observed which can be attributed to the coexistence of long range magnetic ordering and glassy state. The experimental observations were explained with the results obtained by the density functional theory calculation. The presence of double glassy states, large exchange-bias effect and different magnetic phases make this system a potential candidate for spintronic applications.