Magnetization and Mössbauer effect study of the pseudo-binary system (Ti1-xNbx)Fe2

Abstract Mossbauer spectroscopy, magnetization and X-ray diffraction measurements have been done on (Ti 1- x Nb x )Fe 2 compounds in order to investigate the effect of Nb on the magnetic properties of TiFe 2 . The experimental results show that Nb enters the lattice by filling Ti sites thereby forming a continuous phase over the entire range of Nb concentrations. The Mossbauer spectra at 80 K fitted with a magnetic hyperfine field distribution show a continuous decrease in the average magnetic hyperfine field with increasing Nb concentrations as well as several different magnetic configurations for x ≥ 0.3. A similar result was obtained for the spectra at 10 K when samples with x ≥ 0.5 were fitted with a magnetic hyperfine field distribution. Magnetization measurements of M versus H for constant temperature and M versus T for constant magnetic field yield the following results: the pseudoternary compounds are antiferromagnetic in the concentration range 0 ≤ x ≤ 0.5 with the Neel temperature increasing slightly with Nb content up to x = 0.3 followed by a steady decrease as x increases to 0.5. Between x = 0.5 and 0.6 a magnetic phase transition from AF to ferromagnetism occurs. The spontaneous magnetization σ 0 increases with Nb content, reaching a maximum at x = 0.8. For larger Nb contents σ 0 decreases, going to 0 for the pure NbFe 2 phase. The Curie temperature shows behavior similar to that of σ 0 .