The effect of Co doping on structural, magnetic and magnetocaloric properties of La0.8Ca0.2Mn1-xCoxO3 perovskites (0 ≤ x ≤ 0.3)

Studies of the structural, magnetic and magnetocaloric properties of polycrystalline La0.8Ca0.2Mn1-xCoxO3 compounds (0 <= x <= 0.3) perovskite manganites were carried out. Samples were synthesized by sol-gel process and then heated at 1000 degrees C for 3 h. X-ray powder diffraction and magnetic measurements were used to investigate the structural and magnetic properties. Rietveld analysis shows that the samples crystallize in the orthorhombic structure with Pnma space group. Crystallographic analysis shows a variation in lattice parameters as cobalt substitution increases, accompanied by a variation in the interatomic distances and a small increase in MT-O-MT angles (MT = cobalt and manganese). Magnetocaloric studies on La0.8Ca0.2Mn1-xCoxO3 compounds with x = 0 and x = 0.2 have been investigated by measuring the magnetization as a function of temperature. At 2 T, the maximum magnetic entropy |Delta (SM)-M-max| is about 3.09 J . Kg(-1) . K (1) and 1.123 J . Kg(-1) . K (1) for x = 0 and 0.2, respectively. Besides, the RCP value decreases with increasing Co content from 55.845 J . Kg(-1) to 49.971 J . Kg(-1). Also, the existence of Griffiths Phase and its influence in the phase transition is discussed.