“…Assuming the cluster's size to be related to their coupling strength, the ratio of E a / k B and T 0 is used as a measure of coupling/clustering strength among the dynamic entities that freeze at T f . E a /( k B T 0 ) < 1 signifies the strong coupling between the magnetic entities while E a /( k B T 0 ) > 1 indicates the weak coupling 68,74 In our case, E a / k B ∼ 10 T 0 , suggests a weak coupling among the clusters and E a /( k B T 0 ) > 1 had been observed in cluster SG systems 75,76 which is consistent with our system. In view of the above observations, the cluster spin glass state of Sn 0.5 Fe 0.5 O 2− δ at low temperatures results due to the competing AFM and FM interactions.…”