PRECISION ANALYSIS OF QUANTUM CORRECTIONS TO THE CONDUCTIVITY IN DISORDERED CONDUCTORS

We present high resolution measurements of low-temperature resistance and magnetoresistance (DELTArho/rho: +/-5.10(-8)) on two 3D amorphous Ca1-xAlx-alloys (x = 0.25 and 0.4). On the basis of such extreme data accuracy, and using theories of quantum corrections (WL and EEI), in c onjunction with an elaborate fitting procedure, we show that for these metallic glasses a fully consistent description of the experimental d ata in terms of given theory is possible only in the limits of low fie lds and low temperatures. We quantitatively identify the deviations oc curring at higher fields as being due to contributions from the 'class ical' magnetoresistance (approximately B2), and those occurring at hig her temperatures as caused by Ziman-Faber diffraction in metallic glas ses (approximately T2) . Accounting for this, a complete set of solid state parameters is then reliably accessible. In addition to relevant scattering rates tau(PHI)-1 and tau(SO)-1, these are: resistivity rho, diffusivity D, Sommerfeld coefficient gamma, Fermi-wavevector k(F), e lectron/phonon coupling constant lambda, and EEI constants mu = F/2 an d mu. Particularly, what concerns the parameter F, which describes th e effective electron-electron-interaction, and determines whether the material is superconducting or not, an inconsistency in the experiment al literature is resolved. We show that, due to the influence of the ' classical' contribution to magnetoresistance, F can only be obtained f rom the temperature dependence of resistivity.