Spin order and dynamics in the diamondlattice Heisenberg antiferromagnets ${\mathrm{CuRh}}_{2}{\mathrm{O}}_{4}$ and ${\mathrm{CoRh}}_{2}{\mathrm{O}}_{4}$
Here, antiferromagnetic insulators on a diamond lattice are candidate materials to host exotic magnetic phenomena ranging from spinorbital entanglement to degenerate spiral ground states and topological paramagnetism. Compared to other threedimensional networks of magnetic ions, such as the geometrically frustrated pyrochlore lattice, the investigation of diamondlattice magnetism in real materials is less mature. In this work, we characterize the magnetic properties of model Asite spinels CoRh _{2}O _{4} (cobalt rhodite) and CuRh _{2}O _{4} (copper rhodite) by means of thermomagnetic and neutronscattering measurements, and we perform group theory analysis, Rietveld refinement, meanfield theory, and spinwave theory calculations to analyze the experimental results. Our investigation reveals that cubic CoRh _{2}O _{4} is a canonical S = 3/2 diamondlattice Heisenberg antiferromagnet with a nearestneighbor exchange J = 0.63 meV and a Néel ordered ground state below a temperature of 25 K. In tetragonally distorted CuRh _{2}O _{4}, competing exchange interactions between up to thirdnearestneighbor spins lead to the development of an incommensurate spin helix at 24 K with a magnetic propagation vector k _{m} = (0,0,0.79). Strong reduction of the ordered moment is observed for the S = 1/2 spins in CuRh _{2}O _{4} and captured by our 1/ S corrections tomore »
 Authors:

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 Georgia Inst. of Technology, Atlanta, GA (United States)
 Oregon State Univ., Corvallis, OR (United States)
 Georgia Inst. of Technology, Atlanta, GA (United States); Univ. of Cambridge, Cambridge (United Kingdom)
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Univ. of California, Santa Cruz, CA (United States)
 Publication Date:
 Grant/Contract Number:
 AC0500OR22725
 Type:
 Accepted Manuscript
 Journal Name:
 Physical Review B
 Additional Journal Information:
 Journal Volume: 96; Journal Issue: 6; Journal ID: ISSN 24699950
 Publisher:
 American Physical Society (APS)
 Research Org:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
 OSTI Identifier:
 1471939
 Alternate Identifier(s):
 OSTI ID: 1374655
Ge, L., Flynn, J., Paddison, Joseph A. M., Stone, Matthew B., Calder, Stuart A., Subramanian, M. A., Ramirez, A. P., and Mourigal, Martin P.. Spin order and dynamics in the diamondlattice Heisenberg antiferromagnets CuRh2O4 and CoRh2O4. United States: N. p.,
Web. doi:10.1103/PhysRevB.96.064413.
Ge, L., Flynn, J., Paddison, Joseph A. M., Stone, Matthew B., Calder, Stuart A., Subramanian, M. A., Ramirez, A. P., & Mourigal, Martin P.. Spin order and dynamics in the diamondlattice Heisenberg antiferromagnets CuRh2O4 and CoRh2O4. United States. doi:10.1103/PhysRevB.96.064413.
Ge, L., Flynn, J., Paddison, Joseph A. M., Stone, Matthew B., Calder, Stuart A., Subramanian, M. A., Ramirez, A. P., and Mourigal, Martin P.. 2017.
"Spin order and dynamics in the diamondlattice Heisenberg antiferromagnets CuRh2O4 and CoRh2O4". United States.
doi:10.1103/PhysRevB.96.064413. https://www.osti.gov/servlets/purl/1471939.
@article{osti_1471939,
title = {Spin order and dynamics in the diamondlattice Heisenberg antiferromagnets CuRh2O4 and CoRh2O4},
author = {Ge, L. and Flynn, J. and Paddison, Joseph A. M. and Stone, Matthew B. and Calder, Stuart A. and Subramanian, M. A. and Ramirez, A. P. and Mourigal, Martin P.},
abstractNote = {Here, antiferromagnetic insulators on a diamond lattice are candidate materials to host exotic magnetic phenomena ranging from spinorbital entanglement to degenerate spiral ground states and topological paramagnetism. Compared to other threedimensional networks of magnetic ions, such as the geometrically frustrated pyrochlore lattice, the investigation of diamondlattice magnetism in real materials is less mature. In this work, we characterize the magnetic properties of model Asite spinels CoRh2O4 (cobalt rhodite) and CuRh2O4 (copper rhodite) by means of thermomagnetic and neutronscattering measurements, and we perform group theory analysis, Rietveld refinement, meanfield theory, and spinwave theory calculations to analyze the experimental results. Our investigation reveals that cubic CoRh2O4 is a canonical S = 3/2 diamondlattice Heisenberg antiferromagnet with a nearestneighbor exchange J = 0.63 meV and a Néel ordered ground state below a temperature of 25 K. In tetragonally distorted CuRh2O4, competing exchange interactions between up to thirdnearestneighbor spins lead to the development of an incommensurate spin helix at 24 K with a magnetic propagation vector km = (0,0,0.79). Strong reduction of the ordered moment is observed for the S = 1/2 spins in CuRh2O4 and captured by our 1/S corrections to the staggered magnetization. Our work identifies CoRh2O4 and CuRh2O4 as reference materials to guide future work searching for exotic quantum behavior in diamondlattice antiferromagnets.},
doi = {10.1103/PhysRevB.96.064413},
journal = {Physical Review B},
number = 6,
volume = 96,
place = {United States},
year = {2017},
month = {8}
}