Structure and magnetic properties of RFe11.35Nb0.65 and RFe11.35Nb0.65Ny (R=Y, Sm, Gd, Tb, Dy, Ho, Er, and Lu).

摘要: A series of compounds with the ${\mathrm{ThMn}}_{12}$-type structure, R${\mathrm{Fe}}_{11.35}$${\mathrm{Nb}}_{0.65}$ (R=Y, Sm, Gd, Tb, Dy, Ho, Er, and Lu), were synthesized. The corresponding nitrides, obtained by gas-solid reactions, retained same structure as their parent compounds, but a relative volume expansion 3%. Nb atoms occupy 8i sites in ${\mathrm{ThMn}}_{12}$ structure. highest Curie temperatures are 597 K 773 for ${\mathrm{GdFe}}_{11.35}$${\mathrm{Nb}}_{0.65}$ its nitride, respectively. average iron magnetic moment ${\mathrm{\ensuremath{\mu}}}_{\mathrm{Fe}}$ at T=1.5 is 1.9${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$ 2.1${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$ nitrides. By introduction nitrogen, Fe-Fe exchange interaction much strengthened while R-Fe slightly weakened. enhancement influence interstitial nitrogen about 11%. Fe sublattices nitrides have an easy c-axis anisotropy. At K, anisotropy constant ${\mathit{K}}_{1}$(Fe) 25.7 K/f.u. 21.9 reduction 17%. Spin-reorientation transitions observed ${\mathrm{DyFe}}_{11.35}$${\mathrm{Nb}}_{0.65}$ ${\mathrm{ErFe}}_{11.35}$${\mathrm{Nb}}_{0.65}$ compounds. complex behavior low can be explained crystal-field-interaction models. ${\mathrm{SmFe}}_{11.35}$${\mathrm{Nb}}_{0.65}$ compound has field 10.0 T room temperature. Its high temperature magnetization make it potential candidate applications permanent magnet.