Effect on Electrical and Magnetic Behavior of Al–Cu–Fe Quasicrystals During Surface Leaching

In this study, the effect of change in electric and magnetic characteristics of Al–Cu–Fe quasicrystals (QCs), by de-alloying of Al from the surface, was investigated. Dissolution of Al was carried out in NaOH aqueous solution which did not change the icosahedral structure of Al–Cu–Fe; however, it changed the non-magnetic nature of Al–Cu–Fe QCs into the ferromagnetic one. This has never been reported in previous studies on Al–Cu–Fe QCs. The ferromagnetic characteristics of icosahedral Al–Cu–Fe QCs powder (at room temperature and 5 K) were studied in detail using vibrating sample magnetometer (VSM). For the first time, it is reported that the value of susceptibility (χm) of Al–Cu–Fe QCs was in the order of 103 which is considerably greater then χm value of diamagnetic and paramagnetic materials. The VSM data indicate that approximately ≈ 1.5% of the total Fe atoms in icosahedral Al–Cu–Fe QC contribute to magnetism and most of which comes from the leached icosahedral surface. Further, Mössbauer spectroscopy (MS) results of Al–Cu–Fe QC powder samples confirm the presence of high spin Fe3+ ionic state. Linear lines of current–voltage (I–V) graph indicate the Ohmic behavior of samples before and after leaching process.