Inhaltszusammenfassung

The influence of lattice disorder varied by low temperature irradiation with 20 MeV azs-ions and subsequent isochronal thermal annealing on Hall-effect Rn(T), resistivity p(T) and superconducting critical temperature Tc of thin films of the Chevrel-phase PbMo6S s is reported. It is found that the well known, unusual sensitivity of Tc is correlated with drastic changes of normal state transport properties e.g. Rn(T) and p(T). In the low fluence regime (q~< 6.1013 cm -2, To=> 2 K) annealin...The influence of lattice disorder varied by low temperature irradiation with 20 MeV azs-ions and subsequent isochronal thermal annealing on Hall-effect Rn(T), resistivity p(T) and superconducting critical temperature Tc of thin films of the Chevrel-phase PbMo6S s is reported. It is found that the well known, unusual sensitivity of Tc is correlated with drastic changes of normal state transport properties e.g. Rn(T) and p(T). In the low fluence regime (q~< 6.1013 cm -2, To=> 2 K) annealing leads to a monotonous restoration of the initial properties with the main recovery occurring at temperatures as low as 500 K. Contrary to this, annealing of highly disordered samples (q~ 1015 cm -2) creates semiconductor-like conduction behavior. This manifests itself by a strong increase of the electrical resistivity with decreasing temperature which becomes more pronounced at higher annealing temperatures irA. After TA = 800 K the resistivity p(15 K) is enhanced by more than a factor of 1000 with p (15 K)/p (280 K)= 210 compared to as irradiated. Further annealing at 900 K and 1000 K results in the reappearance of metallic p(T)- behavior and superconductivity (Tc>10 K). The observed effects can be understood by systematic changes of the electronic density of states consistent with an earlier proposed defect model.» weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik