The origination of ill-defined layer in organic spin valves

The origination of ill-defined layer in organic spin valves was investigated by using atomic force microscopy (AFM) and Rutherford backscattering (RBS) analysis. It was found that conductive bulges of LSMO film and self-grown pinholes in Alq3 film other than Co inclusions could lead to the formation of ill-defined layer. The morphology of LSMO substrate had a strong influence on that of Alq3 film, LSMO/Alq3 and Alq3/Co interfaces. Moreover, Alq3 film with the thickness of 1-4 nm could be barriers which was explained by small active area and added insulated layer in organic magnetic tunnel junctions.