Phase Diagram and Spin Hamiltonian of Weaklycoupled Anisotropic S=1/2 Chains in CuCl _{2} ^{.}2((CD _{3}) _{2}SO)
Abstract
Fielddependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=(1/2) chain compound CuCl{sub 2}{center_dot}2((CD{sub 3}){sub 2}SO). At zero field the system acquires magnetic longrange order below T{sub N}=0.93 K with an ordered moment of 0.44{micro}{sub B}. An external field along the b axis strengthens the zerofield magnetic order, while fields along the a and c axes lead to a collapse of the exchange stabilized order at {micro}{sub 0}H{sub c}=6 T and {micro}{sub 0}H{sub c}=4 T (extrapolated to zero temperature) and the formation of an energy gap in the excitation spectrum. We relate the fieldinduced gap to the presence of a staggered gtensor and DzyaloshinskiiMoriya interactions, which lead to effective staggered fields for magnetic fields applied along the a and c axes. Competition between anisotropy, interchain interactions, and staggered fields leads to a succession of three phases as a function of field applied along the c axis. For fields greater than {micro}{sub 0}H{sub c}, we find a magnetic structure that reflects the symmetry of the staggered fields. The critical exponent, beta, of the temperature driven phase transitions are indistinguishable from those of the threedimensional Heisenberg magnet, while measurements for transitions driven by quantum fluctuations produce larger valuesmore »
 Authors:

 Johns Hopkins University
 ORNL
 Los Alamos National Laboratory (LANL)
 Brookhaven National Laboratory (BNL)
 Publication Date:
 Research Org.:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Flux Isotope Reactor
 Sponsoring Org.:
 USDOE Office of Science (SC)
 OSTI Identifier:
 931971
 DOE Contract Number:
 DEAC0500OR22725
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review B
 Additional Journal Information:
 Journal Volume: 75; Journal ID: ISSN 01631829
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANISOTROPY; CHAINS; ENERGY GAP; EXCITATION; FLUCTUATIONS; HAMILTONIANS; MAGNETIC FIELDS; NEUTRONS; PHASE DIAGRAMS; SCATTERING; SPECIFIC HEAT; SPIN; SYMMETRY
Citation Formats
Chen, Y., Stone, Matthew B, Kenzelmann, M., Batista, C. D., Reich, D. H., and Broholm, C. L. Phase Diagram and Spin Hamiltonian of Weaklycoupled Anisotropic S=1/2 Chains in CuCl2.2((CD3)2SO). United States: N. p., 2007.
Web. doi:10.1103/PhysRevB.75.214409.
Chen, Y., Stone, Matthew B, Kenzelmann, M., Batista, C. D., Reich, D. H., & Broholm, C. L. Phase Diagram and Spin Hamiltonian of Weaklycoupled Anisotropic S=1/2 Chains in CuCl2.2((CD3)2SO). United States. doi:10.1103/PhysRevB.75.214409.
Chen, Y., Stone, Matthew B, Kenzelmann, M., Batista, C. D., Reich, D. H., and Broholm, C. L. Mon .
"Phase Diagram and Spin Hamiltonian of Weaklycoupled Anisotropic S=1/2 Chains in CuCl2.2((CD3)2SO)". United States. doi:10.1103/PhysRevB.75.214409.
@article{osti_931971,
title = {Phase Diagram and Spin Hamiltonian of Weaklycoupled Anisotropic S=1/2 Chains in CuCl2.2((CD3)2SO)},
author = {Chen, Y. and Stone, Matthew B and Kenzelmann, M. and Batista, C. D. and Reich, D. H. and Broholm, C. L.},
abstractNote = {Fielddependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=(1/2) chain compound CuCl{sub 2}{center_dot}2((CD{sub 3}){sub 2}SO). At zero field the system acquires magnetic longrange order below T{sub N}=0.93 K with an ordered moment of 0.44{micro}{sub B}. An external field along the b axis strengthens the zerofield magnetic order, while fields along the a and c axes lead to a collapse of the exchange stabilized order at {micro}{sub 0}H{sub c}=6 T and {micro}{sub 0}H{sub c}=4 T (extrapolated to zero temperature) and the formation of an energy gap in the excitation spectrum. We relate the fieldinduced gap to the presence of a staggered gtensor and DzyaloshinskiiMoriya interactions, which lead to effective staggered fields for magnetic fields applied along the a and c axes. Competition between anisotropy, interchain interactions, and staggered fields leads to a succession of three phases as a function of field applied along the c axis. For fields greater than {micro}{sub 0}H{sub c}, we find a magnetic structure that reflects the symmetry of the staggered fields. The critical exponent, beta, of the temperature driven phase transitions are indistinguishable from those of the threedimensional Heisenberg magnet, while measurements for transitions driven by quantum fluctuations produce larger values of beta.},
doi = {10.1103/PhysRevB.75.214409},
journal = {Physical Review B},
issn = {01631829},
number = ,
volume = 75,
place = {United States},
year = {2007},
month = {1}
}