Phonon and magnetoelastic coupling in Al0.5Ga0.5FeO3: Raman, magnetization and neutron diffraction studies

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

The structural and magnetic properties of hole doped double perovskite La_1.5Ca_0.5CoFeO₆have been investigated by measuring x-ray photoemission spectroscopy, neutron powder diffraction and magnetization. A ferrimagnetic transition is observed atT_C∼ 167 K. The presence of anti-site disorder (ASD) in La_1.5Ca_0.5CoFeO₆has also been demonstrated. Double re-entrant cluster glass transitions (T₁∼ 11 K andT_S∼ 35 K) were observed which has been attributed to the ASD effect. The presence of both large spontaneous exchange biasH_SEB∼ 2.106 kOe and giant conventional exchange biasH_CEB∼ 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.