摘要：Intermetallic compounds of Dy<sub>2</sub>Fe<sub>16</sub>Ga<sub>1−x</sub>Nb<sub>x</sub> (<i>x</i> = 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 Th<sub>2</sub>Fe<sub>17</sub> structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature <i>Tc</i> ~523 K for <i>x</i> = 0.6 sample is higher than <i>Tc</i> = 153 K of Dy<sub>2</sub>Fe<sub>17</sub>. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for <i>x</i> = 0.0 to 42.46 emu/g for <i>x</i> = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe<sub>3</sub> and NbFe<sub>2</sub> secondary phases at <i>x</i> = 1.0. The hyperfine field of Dy<sub>2</sub>Fe<sub>16</sub>Ga<sub>1−x</sub>Nb<sub>x</sub> decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in <i>s</i> electron density due to the unit cell volume expansion. The substantial increase in <i>Tc</i> of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.
