Electronic structures and Curie temperatures of iron-based rare-earth permanent-magnet compounds

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.1064· OSTI ID:6753043

Woods, J P; Patterson, B M; Fernando, A S; Jaswal, S S; Welipitiya, D; Sellmyer, D J ^[1]

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1. Behlen Laboratory of Physics and Center for Materials Research Analysis, University of Nebraska, Lincoln, Nebraska 68588 (United States)

The modification of the electronic structures of Sm[sub 2]Fe[sub 17[minus][ital x]]Al[sub [ital x]]N[sub [ital y]], NdFe[sub 11]TiN[sub [ital y]], and YFe[sub 12[minus][ital x]]Mo[sub [ital x]] upon alloying and nitriding are examined with self-consistent spin-polarized calculations and soft-x-ray photoemission measurements between 18 and 135 eV. The changes in the Curie temperature [ital T][sub [ital c]] with substitutional modifications and nitrogen addition are modeled with self-consistent spin-polarized electronic structure calculations and the spin-fluctuation theory of Mohn and Wohlfarth which relates the electronic structure to [ital T][sub [ital c]]. The calculations show that the spin-summed density of states at the Fermi energy is related to [ital T][sub [ital c]]. The photoemission spectra are dominated by the Fe 3[ital d] electrons within 3 eV of the Fermi energy in agreement with calculations. Changes in the density of states at the Fermi energy for interstitial and and substitutional modification compare well with calculations. Using photoemission results with experimental magnetic moments for the substitutional modification of the compound Sm[sub 2]Fe[sub 17[minus][ital x]]Al[sub [ital x]], the spin-fluctuation theory predicts a change in [ital T][sub [ital c]] in agreement with the measured change in [ital T][sub [ital c]]. Spin-resolved photoemission spectra for [ital c]-axis oriented Sm[sub 2]Fe[sub 17]N[sub 2.6] with magnetization perpendicular to the surface are presented and compared to theoretical calculations.

• DOE Contract Number: FG02-86ER45262
• OSTI ID: 6753043
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 51:2; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CURIE POINT
ELECTRONIC STRUCTURE
IRON ALLOYS
IRON BASE ALLOYS
MAGNETS
MOLYBDENUM ALLOYS
NEODYMIUM ALLOYS
NITRIDATION
NONDESTRUCTIVE ANALYSIS
PERMANENT MAGNETS
PHYSICAL PROPERTIES
QUATERNARY ALLOY SYSTEMS
RARE EARTH ALLOYS
SAMARIUM ALLOYS
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
TRANSITION TEMPERATURE
X-RAY EMISSION ANALYSIS
YTTRIUM ALLOYS