Ferromagnetic cluster glass in Pr0.7Sr0.3Mn1_xCoxO3 (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 Pr0.7Sr0.3Mn1_xCoxO3(0 < x < 0.15) synthesized by conventional high-temperature solid state reaction, 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(eg)(4) e(g)(2)). All samples exhibit a single magnetic transition from ferromagnetic to paramagnetic phase, with a large distribution in Curie temperature TC (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.