Structural, magnetic and electronic transport properties of amorphous and quasicrystalline Al70Pd20Fe10 thin films

Abstract

We report measurements of transmission electron microscopy, the electrical resistivity, magnetoresistance and Hall effect (HE) in the amorphous and quasicrystalline (QC) phase of . The samples are prepared in situ at K as thin films in the amorphous phase. After preparation, the sample was measured during annealing at different temperatures. The measurements were performed in the temperature range of 1.2–300 K and with fields up to ±8 T. Atomic structure information obtained by transmission electron spectroscopy reveals that the icosahedral local atomic order is already present in the amorphous phase and is improved during annealing to the QC phase. An anomalous contribution in the HE reveals that there is magnetic order present in the amorphous sample, however after annealing the magnetic transition temperature Tc is reduced and finally disappears when the thin films transforms completely into the ordered QC phase. Direct magnetic moment measurements verify the magnetic properties derived from the resistance measurements, such as Curie temperature of 25 K ≤ ≤ 150 K upon annealing. The experimental results related to the atomic structure and the electronic transport properties in both phases, can be explained in the framework of electronic stabilized Hume-Rothery phases, where hybridization effects of Al- with Fe- electrons play an important role.