Random magnetic anisotropy in thin films of amorphous Mn sub 48 B sub 52

Journal Article · Tue Nov 14 23:00:00 EST 1989 · Physical Review (Section) B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.40.9895· OSTI ID:5249899

Kistenmacher, T J; Bryden, W A; Moorjani, K ^[1]

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1. Milton S. Eisenhower Research Center, Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20707-6099 (US)

While crystalline MnB is a ferromagnet ({ital T}{sub {ital c}}=573 K), rf diode-sputtered thin films of composition Mn{sub 48}B{sub 52} are amorphous as ascertained by x-ray scattering and exhibit a low-field, hysteretic, static magnetization peak characteristic of a spin glass. High-field (up to 44 kG) static magnetization data at temperatures ranging between 6 and 200 K are analyzed within the random anisotropy model of Chudnovsky, Saslow, and Serota (Phys. Rev. B 33, 251 (1986)). In this model, the field-dependent magnetization at a given temperature is expressed as {ital M}({ital H})={ital M}(0)(1{minus}{ital CH}{sup {minus}1/2})+{chi}{prime}H, where the lead term follows from the analysis of a ferromagnet with a wandering axis (FWA) and the second term accounts for contributions from induced moments. The {ital T}{sup 3/2} dependence of the saturation magnetization of the FWA contribution, {ital M}(0), at low temperatures is suggestive of spin-wave excitations, while the temperature dependence of the fitting parameters {ital C} and {chi}{prime} consistently identify several characteristic temperatures associated with the magnetic behavior of {ital a}-Mn{sub 48}B{sub 52}, including the low-field spin-glass transition temperature and Curie temperature and the curvature crossover temperature (established from a classical Arrott plot) that separates the FWA state and a pseudoparamagnetic limit.

• OSTI ID: 5249899
• Journal Information: Physical Review (Section) B: Condensed Matter; (USA), Journal Name: Physical Review (Section) B: Condensed Matter; (USA) Vol. 40:14; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
AMORPHOUS STATE
BORIDES
BORON ALLOYS
BORON COMPOUNDS
FILMS
LOW TEMPERATURE
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE ALLOYS
MANGANESE BORIDES
MANGANESE COMPOUNDS
PHYSICAL PROPERTIES
RANDOMNESS
SPIN GLASS STATE
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE