Micro-structural and morphological properties and magnetic behavior of GaΛSb (Λ = Mn, Ni) nanostructured thin films by magnetron co-sputtering

Abstract In this work, we prepared GaMnSb and GaNiSb thin films on glass substrates by DC magnetron co- sputtering system. The substrate temperature (Ts) and deposition time were varied during synthesis process. From µ-XRD measurements, SEM and AFM micrographs, were studied the structural, morphological and topographic properties, respectively. Size grains homogeneous, between 50 nm and 250 nm were obtained when substrate temperature varied between 323 K and 523 K. Annealing process for all samples were realized in situ and subsequent to the deposition stage. Decreased amorphous characteristic when the samples were subjected to high temperatures during annealing process (T ≥ 600 K) was observed. From Auger spectroscopy were identified the MNN and LMM transitions of precursor species, and the presence of manganese and antimony was correlated with the Mn2Sb, Mn2Sb2 and NiSb phases formation on the surface of the samples; these phases were identified by XRD and µ-XRD measurements. Moreover, ferromagnetic-like behavior associated with the presence of the binary phases in GaMnSb samples, and the superparamagnetic properties at low temperature related with NiSb phase in the case of GaNiSb samples, were found. Finally, a qualitative model of thin film formation was proposed.