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

Journal Article · Sun Jan 01 00:00:00 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), Vol. 51:2; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

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