Title :
Invar properties of the interstitial carbides of Nd2Fe 17
Author :
Zhang, X.D. ; Shumsky, M.G. ; James, W.J. ; Yelon, W.B.
Author_Institution :
Graduate Centre for Mater. Res., Missouri Univ., Rolla, MO, USA
fDate :
11/1/1995 12:00:00 AM
Abstract :
High-temperature X-ray diffraction experiments from 50°C to 400°C have been carried out to measure the thermal variations of the lattice parameters of Nd2Fe17Cx (x=0.5, 1.0), which has the rhombohedral structure of the Th2Zn17 type, space group R3¯m. The interstitial carbides Nd2Fe17Cx, together with their parent Nd2Fe17, exhibit Invar-like thermal expansion anomalies below their Curie temperatures, T c. Although the introduction of carbon into Nd2Fe 17 leads to lattice expansion and enhancement of Tc, the observed positive spontaneous magnetostriction of the carbides is comparable with that of Nd2Fe17. It is proposed that such a spontaneous magnetostriction can be ascribed to the occurrence of some short Fe-Fe distances and the strong distance dependence of the positive and negative interactions
Keywords :
Curie temperature; Invar; X-ray diffraction; ferromagnetic materials; interstitials; lattice constants; magnetocaloric effects; magnetostriction; neodymium alloys; permanent magnets; thermal expansion; 50 to 400 C; Curie temperature; Invar properties; Nd2Fe17C; Nd2Fe17Cx; X-ray diffraction; lattice parameters; spontaneous magnetostriction; thermal expansion anomaly; thermal variations; Atomic measurements; Iron; Lattices; Magnetic properties; Magnetostriction; Neodymium; Powders; Temperature; Thermal expansion; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
