Ralph Rosenbaum

A useful Mott-Efros-Shklovskii resistivity crossover formulation for three-dimensional films

Useful and simple 3D crossover expressions are presented for the resistance versus temperature behaviour in highly insulating 3D films. At high temperatures, this theory extrapolates to the Mott variable-range hopping law, and at low temperatures to the Efros - Shklovskii variable-range hopping law. Good agreement is found between the crossover theory and resistance measurements.

Metal-insulator transition in amorphous Si 1 − x Ni x : Evidence for Mott’s minimum metallic conductivity

We study the metal-insulator transition in two sets of amorphous

Magnetoresistance of an insulating amorphous nickel-silicon film in large magnetic fields

{\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{Ni}}_{x}

Specific heat of 5% and 3% 3He-4He solutions under pressure

films. The sets were prepared by different, electron-beam-evaporation-based technologies: evaporation of the alloy, and gradient deposition from separate Ni and Si crucibles. The characterization included electron and scanning tunneling microscopy, glow discharge optical emission spectroscopy, energy dispersive x-ray analysis, and Rutherford back scattering. Investigating the logarithmic temperature derivative of the conductivity,

General resistance crossover expressions for three-dimensional variable-range hopping

w=\mathrm{d}\mathrm{ln}\ensuremath{\sigma}/\mathrm{d}\mathrm{ln}T,

Critical current of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ in strong applied fields

we observe that, for insulating samples,

Critical current of Y1Ba2Cu3O7 in strong applied fields

w(T)

Metallic transport properties of amorphous nickel-silicon films

shows a minimum, increasing at both low and high T. Both the minimum value of w and the corresponding temperature seem to tend to zero as the transition is approached. The analysis of this feature of

Characteristics of granular Al-Al2O3 SQUIDs

w(T,x)

Magnetoresistance of an insulating quasicrystalline AlPdRe film in large magnetic fields

leads to the conclusion that the transition in