Study of magneto-electric coupling between ultra-thin Fe films and PMN-PT using X-ray magnetic circular dichroism

X-ray absorption spectra and magnetic circular dichroism were measured at the Fe L3, 2-edges of an iron wedge deposited on a ferroelectric substrate in the total electron yield mode. Upon switching the ferroelectric polarization from Pup to Pdown, we observe a relative change in the total magnetic moment of 20% for 1.5 nm thin Fe. For 3 nm thin Fe, the relative change is within the sum rule error bar. Taking the sampling depth of the measurement method into account, this difference is compatible with a magnetic anisotropy change taking place in the first interfacial layer in contact with the ferroelectric substrate. We attribute this interfacial coupling to a charge accumulation or depletion at the interface.