Abstract
Magnetic order on the spatially anisotropic triangular lattice of α-NaMnO2 is studied via neutron diffraction measurements. The transition into a commensurate, collinear antiferromagnetic ground state with k=(0.5,0.5,0) was found to occur below TN=22 K. Above this temperature, the transition is preceded by the formation of a coexisting, short-range ordered, incommensurate state below TIC=45 K whose two-dimensional propagation vector evolves toward k=(0.5,0.5) as the temperature approaches TN. At high temperatures (T>TIC), quasielastic scattering reveals one-dimensional spin correlations along the nearest-neighbor Mn-Mn "chain direction" of the MnO6 planes. Our data are consistent with the predictions of a mean-field model of Ising-like spins on an anisotropic triangular lattice, as well as the predominantly one-dimensional Heisenberg spin Hamiltonian reported for this material.
| Original language | English |
|---|---|
| Article number | 144444 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 14 |
| DOIs | |
| State | Published - Oct 31 2018 |
Funding
S.D.W. and R.L.D. gratefully acknowledge support from DOE, Office of Science, Basic Energy Sciences under Award No. DE-SC0017752. The research reported here made use of shared facilities of the UCSB MRSEC (NSF DMR 1720256), a member of the Materials Research Facilities Network ( www.mrfn.org ). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce, in providing the neutron research facilities used in portions of this work. S.D.W. and R.L.D. also acknowledge support from the California NanoSystems Institute (CNSI). S.D.W. and R.L.D. gratefully acknowledge support from DOE, Office of Science, Basic Energy Sciences under Award No. DE-SC0017752. The research reported here made use of shared facilities of the UCSB MRSEC (NSF DMR 1720256), A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce, in providing the neutron research facilities used in portions of this work. S.D.W. and R.L.D. also acknowledge support from the California NanoSystems Institute (CNSI).
| Funders | Funder number |
|---|---|
| California NanoSystems Institute | |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| U.S. Department of Commerce | |
| Office of Science | |
| Basic Energy Sciences | DE-SC0017752 |
| Norsk Sykepleierforbund | DMR1720256 |