The magnetic properties of the Al_(62)Cu_(25.5)Fe_(12.5) alloy in different structural states (from as-quenched disordered state to single-phase quasicrystalline state) that were obtained by various heat treatments have been studied. The concentrations of magnetically active-paramagnetic and magnetically ordered-iron atoms were determined from the Curie constant (C_(CW)) and spontaneous magnetization (I_S) curves, respectively. The Curie constant was determined from the temperature dependences of the magnetic susceptibility that follows the Curie-Weiss law. It was shown that changes in the concentration of iron atoms correlate with changes in the residual electrical conductivity sigma_0, which is determined by the concentration of free charge carriers. The strong dependence of the low-temperature paramagnetism of the Al-Cu-Fe alloys on the lattice perfection is due to the fact that the unpaired spins of iron atoms are formed only in the presence of local lattice distortions of the icosahedral phase.
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