Electronic transport in single crystals and polycrystalline Al 3 Zr : Effect of disorder upon resistivity

We report on electronic transport measurements carried out on ${\mathrm{Al}}_{3}\mathrm{Zr}$ single crystals and a polycrystal. The resistivities of the most conductive samples follow the Bloch-Gr\"uneisen temperature dependence with very similar characteristic temperatures ${\ensuremath{\theta}}_{R}$ around 417 K. Excess Zr and some additional impurities/disorder are responsible for a wide spread of residual resistivities $({\ensuremath{\rho}}_{0})$ in the crystals. In samples with large ${\ensuremath{\rho}}_{0},$ resistivity seems to be dominated over wide ranges of temperature by scattering from vibrating impurities (a mechanism known as electron-phonon-impurity interference). At low temperatures the contribution of the interference term to resistivity is $\ensuremath{\Delta}{\ensuremath{\rho}}_{\mathrm{imp}}=B{\ensuremath{\rho}}_{0}{T}^{2}.$ The very large value of B (as compared with the few data available for other metals) and large ${\ensuremath{\rho}}_{0}$ in this group of samples enabled detection of this unusual electronic scattering up to relatively high temperatures.