Random-field effects in the diluted two-dimensional Ising antiferromagnet Rb/sub 2/Co/sub 0. 7/Mg/sub 0. 3/F/sub 4/

Journal Article · Mon Aug 01 00:00:00 EDT 1983 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.28.1438· OSTI ID:5522409

Birgeneau, R J; Yoshizawa, H; Cowley, R A; Shirane, G; Ikeda, H

We report a comprehensive neutron scattering study of the spin correlations in the diluted two-dimensional (2D) Ising antiferromagnet Rb/sub 2/Co/sub 0.7/Mg/sub 0.3/F/sub 4/ in an applied magnetic field. As predicted by Fishman and Aharony, an applied field in this system produces a random staggered magnetic field. Random fields are expected to have drastic effects on the cooperative behavior of magnets although the detailed behavior remains controversial. It is found that the applied magnetic field, and by inference the concomitant random staggered fields, destroy the 2D long-range order for all temperatures and fields. The structure factor S/sup z/z(Q) = summation/sub r/e/sup i/Qxr ..T/sub N/, taking on values of about 0.7 and -1.2, respectively, at T/sub N/ = 42.5 K. For small but nonzero applied fields the inverse correlation length may be factorized into a random-field part and a thermal part, kappa = kappa/sub RF/+kappa/sub T/, with kappa/sub T/approx.ezz/k/sub B/T where J/sup z/z is the Ising exchange constant.

• Research Organization: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 5522409
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 28:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT FLUORIDES
MAGNETIC PROPERTIES
MAGNESIUM FLUORIDES
RUBIDIUM FLUORIDES
ANTIFERROMAGNETIC MATERIALS
CORRELATIONS
EXPERIMENTAL DATA
ISING MODEL
MAGNETIC FIELDS
NEUTRON DIFFRACTION
PHASE TRANSFORMATIONS
RANDOMNESS
SPIN
STRUCTURE FACTORS
TEMPERATURE DEPENDENCE
VERY LOW TEMPERATURE
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ANGULAR MOMENTUM
COBALT COMPOUNDS
COHERENT SCATTERING
CRYSTAL MODELS
DATA
DIFFRACTION
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
MAGNESIUM COMPOUNDS
MAGNETIC MATERIALS
MATERIALS
MATHEMATICAL MODELS
NUMERICAL DATA
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
RUBIDIUM COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS
360603* - Materials- Properties