Role of the Fe sub-lattice on the Invar anomaly in R{sub 2}Fe{sub 14}B compounds.

Conference · Thu May 15 04:00:00 EDT 2003 · J. Appl. Phys.

DOI:https://doi.org/10.1063/1.1541647· OSTI ID:925043

Yang, N; Dennis, K W; McCallum, R W; Kramer, M J; Zhang, Y; Lee, P L

Thermal expansion anomalies of Nd{sub 2}Fe{sub 14}B and Y{sub 2}Fe{sub 14}Bstoichiometric compounds have been studied by x-ray diffraction with high energy synchrotron radiation using a Debye-Scherrer geometry from room temperature to 1000 K. Y{sub 2}Fe{sub 14}Band Nd{sub 2}Fe{sub 14}B have similar temperature dependence of lattice parameters and bond distances up to their Curie temperatures T{sub c}. The volumetric spontaneous magnetostriction at room temperature for Nd{sub 2}Fe{sub 14}B and Y{sub 2}Fe{sub 14} were determined to be 1.49% and 1.45%, respectively. Among the Fe-Fe bonds, those bonds containing Fe(j2), whose projections are dominantly in the basal plane, have the highest contribution to the Invar effect. These bonds have magnetostrictive strain ranging from 0.4% to 0.8% at room temperature. Above the Curie temperature, Y{sub 2}Fe{sub 14} has an isotropic thermal expansion, while Nd{sub 2}Fe{sub 14}B exhibits slightly anisotropic thermal expansion. The iron sublattices dominate the spontaneous volumetric magnetostriction of Y{sub 2}Fe{sub 14}B and Nd{sub 2}Fe{sub 14}B compounds.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 925043
• Report Number(s): ANL/XFD/CP-108693
• Conference Information: Journal Name: J. Appl. Phys. Journal Issue: 10 Pt. 3 ; May 15, 2003 Journal Volume: 93
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
CURIE POINT
GEOMETRY
INVAR
IRON
LATTICE PARAMETERS
MAGNETIC MATERIALS
MAGNETISM
MAGNETOSTRICTION
STRAINS
SYNCHROTRON RADIATION
TEMPERATURE DEPENDENCE
THERMAL EXPANSION
X-RAY DIFFRACTION