TY - JOUR
T1 - Critical-field anisotropy and fluctuation conductivity in granular aluminum films
AU - Deutscher, G.
AU - Dodds, S. A.
PY - 1977
Y1 - 1977
N2 - We have measured the upper critical field Hc2(θ) for extreme type-II granular aluminum films much thicker than the coherence length and have found them to display a strong temperature-dependent anisotropy . The temperature dependence of the parallel critical field, H(T), shows an infinite slope near Tc, which we interpret as an indication that these films have a layered structure. The perpendicular critical field, H(T), has an upward curvature, reminiscent of the behavior observed in (SN)x and some layered compounds. As a result, the anisotropy ratio decreases strongly as the temperature is lowered. We interpret this behavior as a transition towards zero dimensionality (decoupled grains). We have also measured the fluctuation conductivity σs above Tc. We find that, for films with high values of normal-state resistivity, σs follows a power law characteristic of zero dimensionality far above Tc, and characteristic of two dimensionality closer to Tc, in agreement with the proposed interpretation of the critical-field data.
AB - We have measured the upper critical field Hc2(θ) for extreme type-II granular aluminum films much thicker than the coherence length and have found them to display a strong temperature-dependent anisotropy . The temperature dependence of the parallel critical field, H(T), shows an infinite slope near Tc, which we interpret as an indication that these films have a layered structure. The perpendicular critical field, H(T), has an upward curvature, reminiscent of the behavior observed in (SN)x and some layered compounds. As a result, the anisotropy ratio decreases strongly as the temperature is lowered. We interpret this behavior as a transition towards zero dimensionality (decoupled grains). We have also measured the fluctuation conductivity σs above Tc. We find that, for films with high values of normal-state resistivity, σs follows a power law characteristic of zero dimensionality far above Tc, and characteristic of two dimensionality closer to Tc, in agreement with the proposed interpretation of the critical-field data.
UR - http://www.scopus.com/inward/record.url?scp=4243575268&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.16.3936
DO - 10.1103/PhysRevB.16.3936
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AN - SCOPUS:4243575268
SN - 0163-1829
VL - 16
SP - 3936
EP - 3942
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
IS - 9
ER -