Critical dynamics of a spin-5/2 2D isotropic antiferromagnet

Abstract

We report a neutron scattering study of the dynamic spin correlations in Rb${}_2$MnF${}_4$, a two-dimensional spin-5/2 antiferromagnet. By tuning an external magnetic field to the value for the spin-flop line, we reduce the effective spin anisotropy to essentially zero, thereby obtaining a nearly ideal two-dimensional isotropic antiferromagnet. From the shape of the quasielastic peak as a function of temperature, we demonstrate dynamic scaling for this system and find a value for the dynamical exponent $z$. We compare these results to theoretical predictions for the dynamic behavior of the two-dimensional Heisenberg model, in which deviations from $z=1$ provide a measure of the corrections to scaling.

5 pages, 4 figures. Submitted to Physical Review B, Rapid Communications

References in corpus (2)

• Spin Correlations in the Two-Dimensional Spin-5/2 Heisenberg Antiferromagnet Rb2MnF4
• The correlation length of the Heisenberg antiferromagnet with arbitrary spin S

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• Two-dimensional anisotropic Heisenberg antiferromagnet in a field
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• Uniaxially anisotropic antiferromagnets in a field on a square lattice
• Multicritical behavior of two-dimensional anisotropic antiferromagnets in a magnetic field
• Monte Carlo simulations of $\mathrm{R}{\mathrm{b}}_2\mathrm{Mn}{\mathrm{F}}_4$, a classical Heisenberg antiferromagnet in two-dimensions with dipolar interaction
• Universal behavior of coupled order parameters below three dimensions
• Theoretical prediction of antiferromagnetism in layered perovskite Sr${}_2$TcO${}_4$
• Biconical structures in two-dimensional anisotropic Heisenberg antiferromagnets
• Neutron spin-echo study of the critical dynamics of spin-5/2 antiferromagnets in two and three dimensions
• Critical spin dynamics of the 2D quantum Heisenberg antiferromagnets: Sr_2CuO_2Cl_2 and Sr_2Cu_3O_4Cl_2
• Critical magnetic fluctuations in the layered ruthenates Ca${}_2$RuO${}_4$ and Ca${}_3$Ru${}_2$O${}_7$
• Magnetic properties of Ruddlesden-Popper phases Sr${}_{3-x}$Y${}_x$(Fe${}_{1.25}$Ni${}_{0.75}$)O${}_{7-\delta }$: A combined experimental and theoretical investigation