The Role of Ni for Magnetism in Ti-Zr-Ni Quasicrystals

The interesting structural property of quasicrystals is characterized by exhibition of a five-fold symmetry which is forbidden in crystal. Most of the quasicrystals are discovered in Al- and Ti-based alloys made with rapid quenching indicating that they are metastable. Ti-based quasicrystals are still interesting in terms of structural stability and magnetic state when a sample contains Ni. We prepared metastable Ti_55-xZr₃₃Ni_12+x (x = 0 , 3, 5, 7, 9) metallic ribbons of quasicrystals by rapid quenching method. A pure quasicrystal phase was obtained in a range of 5 les x les 9. The magnetization and magnetic hysteresis were measured by using a vibrating sample magnetometer (VSM). Interestingly, quasicrystal samples made with x = 7 and 9 showed magnetic hysteresis at room temperature, while no evidence for the hysteresis was noted from the samples made with x = 5. This suggests that a magnetic state of quasicrystal is strongly influenced by the Ni concentration. The magnetization values measured at zero-field-cooled (ZFC) and field-cooled (FC) conditions demonstrated little hint of significant difference suggesting that no rapid change in magnetization value is expected.