Universal magnetic behavior of icosahedral F, F2 and F2M Al–Pd–Mn quasicrystals

Magnetic properties of a large set of icosahedral Al–Pd–Mn single crystals were investigated in order to study parameters influencing the moment formation on Mn atoms. Whatever the structural state (F, F2 or F2M), the temperature dependence of the magnetic susceptibility exhibits a universal behavior, which can be explained by a Kondo effect gradually affected by magnetic interactions as the concentration of magnetic Mn increases. The magnetic Mn concentration remains small in all studied samples varying from 3.8 × 10−3 up to 0.2 at.%. Thermal treatments affect the magnetism in a reversible way: slowly cooled samples are systematically found less magnetic than rapidly cooled ones, whatever the composition and structural states. Magnetic properties are so sensitive to composition that they reveal small concentration variations along the growth direction of a single grain obtained by the Czochralski technique. Therefore, magnetism in Al–Pd–Mn quasicrystalline phases is an extremely sensitive probe of atomic arrangement.