Emission studies of the gas-phase oxidation of Mn during pulsed laser deposition of manganates in O₂ and N₂O atmospheres

The plasma produced during pulsed laser deposition of manganate films has been probed using optical emission spectroscopy. The studies have been carried out using Mn, Mn2O3, and La0.67Sr0.33MnO3 (LSMO) as target materials in the presence of two different oxidizing gases: nitrous oxide (N2O) and oxygen (O2). Emission from excited MnO (MnO*) has been observed in all cases resulting primarily from reaction of the ablated Mn atoms with the background gas. Consistent with the oxidation reaction energetics, the emission intensity from MnO* is found to be about an order of magnitude stronger with N2O than with O2. Magnetization measurements of LSMO films show improved magnetic properties of films prepared in N2O compared to O2 at low pressures. The improvement in film quality can be attributed, at least in part, to the increased oxidation of Mn in the plasma plume. © 1996 American Institute of Physics.