Isotropic magnetoresistance of icosahedral Al-Pd-Mn

The temperature dependence of the electrical resistivity rho(T) and the magnetoresistance Delta rho(B,T)/rho(0,T) have been studied along the twofold and fivefold symmetry directions of an icosahedral Al-Pd-Mn in a high quality monograin crystal. To control the influence of any magnetic contribution, samples from the transversal and axial extremes of the crystal were measured along both the twofold and fivefold symmetry directions. The temperature dependence of the resistivity and the magnetoresistance were found to be isotropic. rho(T) and Delta rho(B,T)/rho(0,T) varied in a random way in the transversal direction of the ingot, while systematic variations were observed along the growth direction. These observations could be qualitatively correlated to a gradient of the Mn concentration of below 0.2%/cm in the growth direction of the crystal. [S0163-1829(99)10433-8].