Ferromagnetic cluster glass in Pr_0.7 Sr_0.3 Mn_{1- x}Co_xO₃ (x= 0, 0.05, 0.10 and 0.15) system

We have investigated the structural, morphological and magnetic properties of a series of ABO₃-type perovskite compounds Pr_0.7 Sr_0.3Mn_1-xCo_xO₃ (0 ≤ x ≤ 0.15) synthesized by conventional high temperature solid state reac- tion, which strongly depends on the doping level x. The room temperature powder X ray diffraction data shows the single-phase nature of the sample and confirms the orthorhombic crystal structure with Pnma space group. The SEM images show that the grains are dispersed in shape and size. Energy dispersive X-ray analysis (EDAX) confirms the expected stoichiometry of all samples. Upon Co doping on the Mn-site, the lattice parameters, the unit cell volume and the Mn O Mn bond angle are slightly reduced from x = 0.05 to x = 0.15. The M H curves shows saturation magnetizations almost independent of Co contain, confirming that Co³⁺ replaces Mn³⁺ in B sites and, in addition, Co³⁺ is in high spin configuration (t_eg⁴ eg²). All samples exhibit a single magnetic transition from ferromagnetic to paramagnetic phase, with a large distribution in Curie temperature T_C (260, 220, 180 and 160 K for x = 0, 0.05, 0.10 and 0.15 respectively) and an increase in magnetization M at low temperature. The results are promising for magnetic refrigeration materials and spintronic devices and warrant further investigation.