skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Neutron spin-echo study of the critical dynamics of spin- 5 2 antiferromagnets in two and three dimensions

Journal Article · · Physical Review B
 [1];  [1];  [2];  [3];  [4]
  1. Max-Planck-Institut fur Festkorperforschung, Stuttgart (Germany); Max Planck Society Outstation at the Forschungsneutronenquelle Heinz Maier-Leibnitz (MLZ), Garching (Germany)
  2. Max-Planck-Institut fur Festkorperforschung, Stuttgart (Germany); Diamond Light Source Ltd., Oxfordshire (United Kingdom)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  4. Max-Planck-Institut fur Festkorperforschung, Stuttgart (Germany)

Here, we report a neutron spin-echo study of the critical dynamics in the S= 5 2 antiferromagnets MnF2 and Rb2MnF4 with three-dimensional (3D) and two-dimensional (2D) spin systems, respectively, in zero external field. Both compounds are Heisenberg antiferromagnets with a small uniaxial anisotropy resulting from dipolar spin-spin interactions, which leads to a crossover in the critical dynamics close to the Néel temperature, TN. By taking advantage of the μeV energy resolution of the spin-echo spectrometer, we have determined the dynamical critical exponents z for both longitudinal and transverse fluctuations. In MnF2, both the characteristic temperature for crossover from 3D Heisenberg to 3D Ising behavior and the exponents z in both regimes are consistent with predictions from the dynamical scaling theory. The amplitude ratio of longitudinal and transverse fluctuations also agrees with predictions. In Rb2MnF4, the critical dynamics crosses over from the expected 2D Heisenberg behavior for T » TN to a scaling regime with exponent z = 1.387(4), which has not been predicted by theory and may indicate the influence of long-range dipolar interactions.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1466698
Alternate ID(s):
OSTI ID: 1264792
Journal Information:
Physical Review B, Vol. 94, Issue 1; Related Information: © 2016 American Physical Society.; ISSN 2469-9950
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

References (51)

The theory of superlattice critical scattering journal January 1981
Inelastic Neutron Scattering from Mn F 2 in the Critical Region journal October 1971
Absence of Ferromagnetism or Antiferromagnetism in One- or Two-Dimensional Isotropic Heisenberg Models journal November 1966
The resolution function in neutron diffractometry. I. The resolution function of a neutron diffractometer and its application to phonon measurements journal September 1967
Spin correlations in the two-dimensional spin-5/2 Heisenberg antiferromagnet journal September 1998
Magnetic excitations in pure, lightly doped, and weakly metallic La 2 CuO 4 journal December 1992
Dynamic critical exponent z in some two-dimensional models journal August 1981
Spin-Wave Analysis of the Quadratic-Layer Antiferromagnets K 2 Ni F 4 , K 2 Mn F 4 , and Rb 2 Mn F 4 journal July 1973
The resolution function in neutron spin-echo spectroscopy with three-axis spectrometers journal November 2003
Spin-wave stiffness of the Heisenberg antiferromagnet at zero temperature journal September 1994
Critical dynamics of isotropic dipolar antiferromagnets journal June 1990
Critical Spin Dynamics of the 2D Quantum Heisenberg Antiferromagnets Sr 2 CuO 2 Cl 2 and Sr 2 Cu 3 O 4 Cl 2 journal April 2001
A neutron resonance spin echo spectrometer for quasi-elastic and inelastic scattering journal July 1987
Critical magnetic fluctuations in MnF2 journal November 1969
Nuclear Magnetic Relaxation near the Curie Temperature journal August 1962
Critical dynamics of the simple-cubic Heisenberg antiferromagnet RbMnF 3 : Extrapolation to q = 0 journal March 2003
Temperature and Spin Dependent Correlation Length of the Quantum Heisenberg Antiferromagnet on the Square Lattice journal October 1996
Critical behavior of the three-dimensional Heisenberg antiferromagnet RbMnF 3 journal March 1998
Antiferromagnetic Resonance in Mn F 2 journal May 1959
Spin Correlations in an Isotropic Spin- 5 / 2 Two-Dimensional Antiferromagnet journal January 1999
Spin fluctuations in random magnetic-nonmagnetic two-dimensional antiferromagnets. I. Dynamics journal May 1977
Polarization Analysis of Thermal-Neutron Scattering journal May 1969
Role of Spin-Nonconserving Forces in the Critical Dynamics of Fe at the Curie Point journal October 1982
Neutron Diffraction Studies of Antiferromagnetism in Manganous Fluoride and Some Isomorphous Compounds journal June 1953
Critical Magnetic Neutron Scattering from Ferrous Fluoride journal January 1972
Critical dynamics of a spin- 5 2 two-dimensional isotropic antiferromagnet journal March 2001
Critical exponents and equation of state of the three-dimensional Heisenberg universality class journal April 2002
Neutron scattering study of the two-dimensional spinS=1/2 square-lattice Heisenberg antiferromagnet Sr2CuO2Cl2 journal December 1995
Spin dynamics and spin correlations in the spinS=1 two-dimensional square-lattice Heisenberg antiferromagnet La2NiO4 journal December 1995
Critical dynamics in isotropic ferromagnets journal November 1984
Neutron Scattering Investigation of Phase Transitions and Magnetic Correlations in the Two-Dimensional Antiferromagnets K 2 Ni F 4 , Rb 2 Mn F 4 , Rb 2 Fe F 4 journal March 1970
Dynamic Scaling Theory for Anisotropic Magnetic Systems journal March 1970
Neutron resonance spin echo, bootstrap method for increasing the effective magnetic field journal January 1988
Staircases of magnetic structure along the axial direction in the layered magnet Rb 2 MnF 4 journal July 1987
Two-dimensional quantum Heisenberg antiferromagnet: Effective-Hamiltonian approach to the thermodynamics journal December 1997
Theory of dynamic critical phenomena journal July 1977
The NRSE-TAS spectrometer at the FRM-2 journal December 2002
Crossover scaling functions for exchange anisotropy journal September 1974
Nuclear-Magnetic-Resonance Studies of Critical Phenomena in Mn F 2 . I. Time-Average Properties journal June 1966
Critical Magnetic Scattering in K 2 Ni F 4 journal March 1971
Crystal Statistics. I. A Two-Dimensional Model with an Order-Disorder Transition journal February 1944
Crossover effects in dynamic critical phenomena in MnF2 and FeF2 journal July 1970
Scaling Laws for Dynamic Critical Phenomena journal January 1969
Critical dynamics of magnets journal October 1994
Dynamic correlations in a classical two-dimensional Heisenberg antiferromagnet journal July 1990
Critical phenomena and renormalization-group theory journal October 2002
Neutron spin echo: A new concept in polarized thermal neutron techniques journal April 1972
Critical Behavior of Magnets with Dipolar Interactions. I. Renormalization Group near Four Dimensions journal October 1973
Lifetimes of Antiferromagnetic Magnons in Two and Three Dimensions: Experiment, Theory, and Numerics journal July 2013
Spin correlations in the two-dimensional S=1 Heisenberg antiferromagnet journal February 1990
Spin correlations in the 2D Heisenberg antiferromagnet Sr 2 CuO 2 Cl 2 : Neutron scattering, Monte Carlo simulation, and theory journal February 1994

Figures / Tables (10)