Inhaltszusammenfassung

Amorphous Zr100?xFex ribbons have been produced by melt spinning in the composition range 20?x?43. The superconducting transition temperature Tc is used as a probe for studying structural changes in the zirconium?rich alloys. Modifications of the short?range order are controlled by sample composition, by annealing at temperatures below the crystallization temperature (relaxation), and by low?temperature irradiation with heavy ions. In contrast to amorphous Zr?(Cu, Ni, Co) alloys, the critical...Amorphous Zr100?xFex ribbons have been produced by melt spinning in the composition range 20?x?43. The superconducting transition temperature Tc is used as a probe for studying structural changes in the zirconium?rich alloys. Modifications of the short?range order are controlled by sample composition, by annealing at temperatures below the crystallization temperature (relaxation), and by low?temperature irradiation with heavy ions. In contrast to amorphous Zr?(Cu, Ni, Co) alloys, the critical temperature Tc in the Zr?Fe system increases with increasing annealing temperature. Low?temperature irradiations, on the other hand, lead to a decrease in Tc, which levels off at a value identical for as?quenched and relaxed samples. The results are discussed on the basis of an association model. In the amorphous state, the iron?poor alloy decomposes into iron?rich associates (possibly with Zr2Fe stoichiometry) embedded in a superconducting matrix, slightly improverished in iron, which is described as a regular solution of the components. The composition dependence of the electrical resistivity and the Vickers hardness, as well as previous Mössbauer experiments, indicate the existence of two different associates for x>30, with concentrations of approximately 33 and 50 at.?% Fe, respectively.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik