Effect of Co substitution on crystal structure and magnetic property of La0.85Ag0.15Mnl-yCoyO3 (y = 0 to 1) compounds

La0.85Ag0.15Mnl-yCoyO3 compounds have been prepared for y 0 to 1 in single phase form. XRD patterns were recorded at room temperature and these patterns were analyzed with the help of Fullprof program by employing Rietveld refinement technique. The XRD patterns for 30 ≤ y ≤ 0.70 could be refined by using Pbnm space group. However the patterns for the samples y < 0.30 and y > 0.70 could be refined by using R3c space group. The typical lattice parameters are found to be, a = 5.480(0.002) A, b =5.519(0.003) A, and c = 7.771(0.004)A for y = 0.50. Temperature variations of ac susceptibility down to 20K were measured at an ac field amplitude of 6Oe. The samples for y ≤ 0.70 exhibit paramagnetic to ferromagnetic transitions. The ferromagnetic transition temperature, Tc is found to decrease with increase in 'Co' concentration up to y ≤ 0.30 and however higher Tc has been observed for x=0.50 and 0.70 samples compared to other doped samples. (author)