The Role of the N 2 Atmosphere in the Epitaxial Growth of MnO via Pulsed Laser Deposition

Abstract

The role of ambient gas in the epitaxial growth of manganese oxides on MgO by pulsed laser deposition was investigated by performing complex morphological and structural characterization of thin films while simultaneously monitoring the growth process with electrical probes. The growth in N 2 atmospheres leads to the formation of highly oriented MnO coatings that present compressive in-line stress and contain highly oriented defects, which are induced during growth by the high kinetic energy of the plasma. The presence of O 2 during unlocking the growth of highly crystalline Mn 3 O 4 rotated by 45 deg to MgO, with X-ray Photoelectron Spectroscopy (XPS) measurements showing the contribution of the MnO bonding state on the surface on Mn 3 O 4 due to ambient contamination of the sample. The ability of each atmosphere to promote the growth of two selected oxide phases was shown by both ellipsometry and infrared spectroscopy measurements. The in-situ monitoring of growth highlights the ion acceleration caused by the use of N 2 compared with O 2 and the formation of a plasma environment that is optimal for the formation of molecular species as well as a strong oxide contribution to growth.