Study of the Effect of Cation Non-Stoichiometry of (La_0.85Sr_0.15)_yMnO₃ Manganite Single Crystals on the Magnetic Properties

The influence of cation inhomogeneity on magnetic and electron transport properties of (La0.85Sr0.15)yMnO3 (y=0.92-0.97) single crystals were studied. It was found that both the temperature of ferromagnetic ordering TC and the temperature of orbital ordering TOO are increased with the Mn content decreasing. For all six samples studied two peaks on magnetoresistance curves were observed: the first near TC and the second close to TOO. The magnetic field does not affect the position of the former maximum, while it moves the latter towards lower temperatures.