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The anomalous Hall effect (AHE) in the Heusler compounds Co 2 FeSi and Co 2 FeAl is studied in dependence of the annealing temperature to achieve a general comprehension of its origin. We have demonstrated that the crystal quality affected by annealing processes is a significant control parameter to tune the electrical resistivity ρ xx as well as the anomalous Hall resistivity ρ ahe . Analyzing the scaling behavior of ρ ahe in terms of ρ xx points to a temperature-dependent skew scattering as the dominant mechanism in both Heusler compounds.

Mn3−xGa (x = 0.1, 0.4, 0.7) thin films on MgO and SrTiO3 substrates were investigated with magnetic anisotropy perpendicular to the film plane. An anomalous Hall-effect was observed for the tetragonal distorted lattice in the crystallographic D022 phase. The Hall resistivity xy was measured in a temperature range from 20 to 330 K. The determined skew scattering and side jump coefficients are discussed with regard to the film composition and used substrate and compared to the crystallographic and magnetic properties. arXiv:1212.4019v1 [cond-mat.mtrl-sci]

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We fabricated superconducting MgB2 thin films on (001) MgO substrates. The samples were prepared by magnetron rf and dc co-sputtering on heated substrates. They were annealed ex-situ for one hour at temperatures between 450 • C and 750 • C. We will show that the substrate temperature during the sputtering process and the post annealing temperatures play a crucial role in forming MgB2 superconducting thin films. We achieved a critical onset temperature of 27.1 K for a film thickness of 30 nm. The crystal structures were measured by x-ray diffraction.