Quantitative Depth Profiling of Interfacial Moments in Paramagnetic CoO in Py/CoO bilayer.

We have employed soft x-ray resonant magnetic reflectometry to determine the depth dependence of the net ferromagnetic moment in a Permalloy/CoO bilayer \textit{above} the N\'{e}el point of the antiferromagnetic CoO at 300K. \textit{Quantitative element specific }depth dependent charge and magnetization density profiles have been determined by analyzing the specular reflectivity data at the L$_{3}$ edges of Co and Ni using resonant magnetic scattering theory in the Distorted Wave Born Approximation. We have found that a thin interfacial layer with charge density different from either the Permalloy (Py) or CoO forms at the Py/CoO interface. This layer is magnetic even at room temperature and has a \textit{different} temperature dependence of magnetization compared to Py. We have put the depth profile of magnetization in an \textit{absolute scale} by combining the results of reflectivity measurements and SQUID magnetometry. Work of SKS and MBM supported by DOE.