Plasma Species During Low Pressure Plasma Spraying of La1-xSrxFe1-yCoyO3

La_1-xSr_xFe_1-yCo_yO_3-δ (LSFC) perovskites are potential candidates for preparation of oxygen separation membranes. Low pressure plasma spraying is a promising technique for preparation of thin and dense LSFC-based oxygen separation membranes. Detailed knowledge of the plasma species existing in the plasma jet is essential for optimization of the plasma spray parameters and the microstructure of the deposited coatings. The optical emission spectra of LSFC in low pressure (~ 200 Pa) Ar-He plasmas with different compositions have been investigated.  The main optical emission lines  can be attributed to neutral and excited metal species like La(I), La(II), Sr(I), Sr(II), Fe(I) as well as O(I) and O(II)  species. Additional lines observed in the spectra suggest the presence of molecular species. These results are cross-checked with Knudsen mass spectrometry and inductively coupled-plasma (ICP) chemical analysis of the coatings.