ISSN:
1434-6036
Schlagwort(e):
61.43.-j
;
61.80.Jh
;
81.30.Bx
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract In1−x Pd x films with 0.2≦x≦0.75 have been prepared by vapour quenching at 4.2 K or 77 K, respectively. To test whether amorphous (a-) phases can be obtained in this way, the resistance behavior and the electron diffraction patterns of the as-prepared and annealed films were studied insitu. For films withx=0.25 additional information could be acquired from their superconducting behavior. Combining these results one concludes that a-phases exist for the compositional range 0.2≦x≦0.6, which are stable up to crystallization temperaturesT x within the range 250 K≦T x ≦420 K. Irradiation of the crystallized films at low temperatures (4.2 K or 77 K) with heavy ions (350 keV Ar+ or Kr+) leads to complete re-amorphization. Forx=0.67 corresponding to InPd2 a nanocrystalline (n-) phase is obtained by vapour quenching at 77 K as inferred from x-ray diffraction. AtT x =700 K, thesen-films exhibit a drop of the electrical resistance indicating the beginning of significant grain growth. After recooling, Kr+ bombardment at 77 K does not restore the high electrical resistance of the as-quenchedn-film. This result can be used as a criterion when studying quenched films withx=0.625 corresponding to In3Pd5. In this case, a resistance drop is found atT x =600 K, but the diffraction techniques do not allow an uniquevocal distinction between amorphous and nanocrystalline. This becomes possible by low temperature ion irradiation after annealing atT〉T x . The bombardment results in resistance changes, which saturate well-below the value of the as-quenched sample implying nanocrystallinity for the latter. Based on this criterion, a ‘phase’-diagram for quenched In1−x Pd x is provided with 0≦x≦1 containing the newly detecteda- andn-phases.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01313015
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