Systematic determination of the thickness of a thin oxide layer on a multilayered structure by using an X-ray reflectivity analysis

X-ray reflectometry was used to determine the chemical structure of oxidized Permalloy films grown at different oxidation times. The oxidation time-dependent thickness, roughness and chemical density of each layer were examined simultaneously using the Parratt formalism. With increasing oxidation time, the Permalloy thickness decreased while forming a new oxide layer. After oxidation for 40 sec, the Permalloy film’s thickness remained the same for further oxidation, indicating the formation of an oxidation barrier with a scattering length density much lower than that of the Permalloy. The interfacial roughness between the interface layer and the top protective layer remained the same regardless of the oxidation time.