Magnetic properties of AlPdMn approximant phases

We investigated the magnetic properties of the following approximants of qu asicrystals in the Al(Si)-Pd-Mn system: two cubic compounds, 1/1-Al68Pd11Mn 14Si7 and 2/1-Al70Pd24Mn6, and three orthorhombic compounds xi'-Al71.9Pd23. 5Mn4.6, T-Al-73.1 Pd5.2Mn21.7, and T-Al78.5Pd4.9Mn16.6 NO magnetic Mn atoms are present in the 2/1 and xi' phases or in the Mn-poor T phase. In contra st, a fraction of the Mn atoms carry magnetic moments in the Mn-rich T phas e in which a spin-glass transition occurs at 14 K, and in the 1/1 phase in which a ferromagnetic transition occurs at 8.8 K. The crystallographic site s responsible for the magnetism were identified From spin-polarized band-st ructure calculations; this allows us to discuss the origin of magnetism in both approximant and quasicrystal structures.