Microstructure and phase formation of Heusler thin film compounds

Heusler compounds are promising materials to be applied effectively as highly spin-polarized medium (or components) in spintronic devices. To prove their chances the microstructure, the phase formation, and the chemical homogeneity of sputtered thin films of Co MnSi and Co Cr Fe Al were studied by in-situ TEM observations as well as by analytical characterizations. The observed grain growth and phase formation in dependence on temperature agrees well with the results of measurements of the film resistivity. The chemical homogeneity varies and depends on the deposition process during thin film preparation, especially the incorporation of oxygen is an unwanted effect.