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 04:00:00 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), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 28:3; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

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