Griffiths Phase, Re-Entrant Spin-Glass Behaviour and Schottky Anomaly in Anti-Site Disordered Double Perovskite Pr2MnNiO6

In the present study, the effect of anti-site disorder is explored on the magnetic properties of Pr2MnNiO6. Due to anti-site disorder, a reduced TC preceded by a Griffith phase has been observed. At low temperatures, we also report the development of the unconventional spin glass phase in co-existence with the cluster-like ferromagnetic order. The signature of the re-entrant spin glass phase is revealed by the frequency-dependent ac-susceptibility measurements. The spin glass behavior is also supported by the slow decay of thermo-remanent magnetization. A broad Schottky anomaly has been observed in the specific heat data near 10 K, along with a linear spin-glass term that was suppressed in the magnetic field of 5T. The analysis of the specific heat data indicates the presence of true singlet state of ground state of Pr3+ in Pr2MnNiO6