Microstructure and morphology of MgO thin film with different magnetic underlayers

Abstract The MgO thin films were deposited on various magnetic layers at room temperature by magnetron sputtering. The microstructure and surface morphology of the MgO films were investigated by high-resolution transmission electron microscopy. The results showed that bottom ferromagnetic layer and the MgO thickness are essential factors affecting the quality of the MgO layer. The surface roughness increases with the thickness of the MgO layer. Highly (0 0 1) oriented MgO crystalline films were grown on CoFeB and CoFeC underlayers. On the contrary, the crystallinity of the MgO layer is relatively poor and it shows a wavy interface as the MgO layer was deposited on the Co underlayer.