Low-temperature resistivity and magnetoresistance of the quasicrystalline icosahedral ${\mathrm{Al}}_{80}$${\mathrm{Mn}}_{20}$ and decagonal ${\mathrm{Al}}_{78}$${\mathrm{Mn}}_{22}$ alloys

Resistivity and magnetoresistance measurements are reported for the icosahedral I-${\mathrm{Al}}_{80}$ ${\mathrm{Mn}}_{20}$ and the decagonal T-${\mathrm{Al}}_{78}$ ${\mathrm{Mn}}_{22}$ quasicrystalline alloys. The zero-field resistivity ρ(T,H=0), was measured in the range 0.4–50 K. Both samples exhibited a -${\log }_{10}$T dependence for ρ(T,H=0) over a broad range of temperatures, followed by an approach to a constant value at the lowest temperature. The longitudinal magnetoresistance, ${\rho }_L$(T,H), which was measured for magnetic fields H up to 75 kOe and for T=1.5 and 4.2 K, is positive for the I-phase sample and negative for the T-phase one. The transverse magnetoresistance, ${\rho }_T$(T,H), is negative for both samples. The values measured for ${\rho }_L$(T,H) and ${\rho }_T$(T,H) are comparable to the ones measured in conventional metallic spin glasses.