Ferromagnetic metal to cluster-glass insulator transition induced by A-site disorder in manganites

The magnetotransport behaviors of a series of rare earth manganites with the same $A$ -site cational mean radius and different $A$ -site ionic radii variance ($A$ -site disorder) are investigated. It is found that the system’s ground state transforms from ferromagnetic metal to cluster-glass insulator with increasing $A$ -site disorder. In the cluster-glass state, the magnetization shows the steplike behavior, indicating the existence of short-range magnetically ordered clusters. The significant effect of the $A$ -site disorder on the electronic phase separation is revealed by detecting the cluster-glass ground state at low temperature.