Study the Anomaly in the Magnetic Properties of Invar Alloys by using X-ray Diffraction and Mossbauer Spectra

摘要

In this research, Fe _( 100-x ) Ni _( x ) nanoparticle alloys with x = 29, 32 and 37 is studied. X-ray diffraction patterns were obtained at room temperature confirmed the coexistence of both b.c.c and f.c.c phases for x = 29 and 32. However only f.c.c phase was observed for x = 37 Mossbauer Spectroscopy (MS) shows an anomaly in the occurrence of a paramagnetic structure characteristic of the low-spin (anti taenite) f.c.c phases, in addition to the magnetic materials characteristic of the b.c.c phase and the high-spin f.c.c phase obtained at high-spin f.c.c phase observed in XRD patterns. MS technique proves was an effective instrument for studying and prepared nanoparticle system. The anomaly in the nanoparticle magnetic alloys is due to competing ferromagnetic and antiferromagnetic interactions which arise as a result of fluctuations in the interatomic spacing.