On the magnetism of C14 Nb(Fe_89.4Al_10.6)₂ Laves phase intermetallic compound

The C14 Nb(Fe_89.4Al_10.6)₂ Laves phase intermetallic compound was investigated by DC magnetization (M) measurements performed in the temperature (T) interval from 20 toto 175K, under an applied magnetic field (H) ranging between 50 and 1250 Oe. Magnetization curves were recorded in the field-cooled (FC) and in the zero-field-cooled (ZFC) modes. They clearly showed an irreversible character that vanished at H = 1250 Oe. Both magnetization curves exhibited welldefined peaks around TN = 72.3K whose positions were H-independent, so they were identified as the compound's Neel temperature. The existence of the irreversibility whose degree decreases with H testifies to a re-entrant character of magnetism in the studied compound. An increase of both MFC and MZFC observed below TN likely indicates a mixed, i.e., ferromagnetic and antiferromagnetic ground magnetic state of the studied system.