Document type:
Zeitschriftenaufsatz
Author(s):
Mitchell, P. W.; Cowley, R. A.; Yoshizawa, H.; B̈oni, P.; Uemura, Y. J.; Birgeneau, R. J.
Title:
Critical Behavior of the Three-Dimensional Site-Random {{Ising}} Magnet: ${\mathrm{Mn}}_{\mathrm{x}}$${\mathrm{Zn}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{F}}_{2}$
Abstract:
Neutron scattering has been used to study the critical behavior of the site-random Ising system, MnxZn1-xF2, for x=0.75 and 0.50. With the x=0.75 sample, which is of particularly high quality, measurements were possible over nearly three decades, 4\texttimes{}10-4$<\Vert$t$\Vert{}<$2\texttimes{}10-1 both above and below TN; the resulting exponents are $\nu$=$\nu$'=0.715$\pm$0.035 and $\gamma$=$\gamma$'=1.364$\pm$0.076, and the corresponding amplitude ratios are 0.69$\pm$0.02 and 2.45$\pm$0.15, respectively. These agree well with values obtained in FexZn1-xF2 for x=0.46 and 0.50 and with theoretical predictions for the random exchange Ising model. With the x=0.5 sample, high-energy resolution scans were carried out in the critical region below TN; these experiments indicate that the predicted elastic Lorentzian-squared scattering is too small in magnitude to be measured and specifically that it does not affect the amplitude ratios given above.
Journal title:
Physical Review B
Year:
1986
Journal volume:
34
Month:
oct
Journal issue:
Pages contribution:
4719
Fulltext / DOI: