Study of Structural, Magnetic, and Mossbauer Properties of Dy₂Fe₁₆Ga_1−xNb_x (0.0 ≤ x ≤ 1.0) Prepared via Arc Melting Process

Intermetallic compounds of Dy₂Fe₁₆Ga_1−xNb_x (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th₂Fe₁₇ structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy₂Fe₁₇. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe₃ and NbFe₂ secondary phases at x = 1.0. The hyperfine field of Dy₂Fe₁₆Ga_1−xNb_x decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.