Magnetic circular dichroism of LaMn1-xAlxO3+δ series of samples

We report magnetic circular dichroism (MCD) studies on the polycrystalline LaMn1-xAlxO3+δ series with x=0-0.2. The Mn-2p MCD was recorded in the temperature range from 45 to 300 K for samples with x=0, 0.075, 0.1 and 0.15. It was seen that unlike ac-susceptibility no second transition in MCD was observed at lower temperatures in the samples with x≥0.075 indicating that it is not intrinsic to the samples but arise out of the dynamics of ferromagnetic clusters in the polycrystalline sample. More significantly, the MCD signal persists even 100 K above the ferromagnetic TC confirming that the observation of the magnetic correlation above TC in bulk measurement is intrinsic to this type of systems