Electronic and magnetic properties and phase diagrams of (La1–XRX)0.7Ca0.3MnO3 compounds with R ˭ Sm, Gd, Ho or Er

Abstract Electronic and magnetic properties of the perovskite-like compounds of (La1–xRx)0.7Ca0.3MnO3 (R ˭ Sm, Gd, Ho or Er; 0 ⩽ x ⩽ 1) have been studied by measuring electrical resistance and magnetization. Depending on x in all the compounds examined, a transition from a ferromagnetic metal to a paramagnetic insulator or to a spin-glass insulator state appears. These electronic and magnetic properties are found to depend not only on the tolerance factor t but also on the variance (second moment) [sgrave]2 of the A-site ion radii distribution, and the phase diagram has been established by using t and [sgrave]2 based on the results of the study and the results previously obtained by the present authors and many other researchers.