Electronic structure and magnetic properties of a new class of hard magnets: R sub 2 Fe sub 17 N sub x (abstract)

Journal Article · Fri Nov 15 04:00:00 EST 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.350062· OSTI ID:5053191

Jaswal, S S; Sellmyer, D J ^[1]; Hadjipanayis, G C ^[2]; Yelon, W B ^[3]

---

1. Nebraska Univ., Lincoln, NE (United States). Behlen Lab. of Physics
2. University of Delaware, Newark, Delaware (United States). Department of Physics
3. University of Missouri Research Reactor, Columbia, Missouri (United States)

Recently discovered R{sub 2} Fe{sub 17}N{sub {ital x}} (R=rare earth, {ital x}{similar to}3) compounds look promising as permanent-magnet materials. The addition of N to R{sub 2}Fe{sub 17} compounds almost doubles their Curie temperatures.{sup 1} It also give rise to uniaxial anisotropy in the Sm compound. We have performed spin-polarized self-consistent electronic structure calculations in order to understand the magnetic properties. Neutron diffraction and photoemission measurements are used to obtain information on nitrogen site occupancies and electronic structure. For Y{sub 2}Fe{sub 17}N{sub 3}, the calculated site-dependent Fe moments vary significantly from those for Y{sub 2}Fe{sub 17} (up to {similar to}1.7 {mu}{sub {ital B}}), and the total moment per cell agrees very well with experiment. The expansion of the lattice due to nitrogenation lowers the overlap among the Fe atoms in the ion-only planes thereby increasing their magnetic moments. This leads to an increase in their interatomic exchange interactions and hence the Curie temperature. The Fe atoms in the vicinity of the N atoms overlap strongly with the latter and thus their moments decrease.{sup 2}

• DOE Contract Number: FG02-86ER45262
• OSTI ID: 5053191
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 70:10; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRONIC STRUCTURE
EMISSION
IRON COMPOUNDS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETS
MATHEMATICS
NEUTRON DIFFRACTION
NITROGEN COMPOUNDS
NUMERICAL ANALYSIS
PERMANENT MAGNETS
PHOTOEMISSION
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SECONDARY EMISSION
TRANSITION ELEMENT COMPOUNDS