{"title":"Neutron Scattering Investigation of the Magnetic Excitations in CoBr 2","authors":"H. Yoshizawa, Koji Ubukoshi, K. Hirakawa","doi":"10.1143/JPSJ.48.42","DOIUrl":null,"url":null,"abstract":"In order to investigate the two-dimensionality and the easy plane anisotropy, the spin waves propagating along the [h, 0, 0], [h, h, 0], [h, 0.5h, 0] and [0, 0, l ] directions in CoBr 2 were observed using inelastic neutron scattering technique. The spin dynamics of CoBr 2 can be described by the anisotropic exchange Hamiltonian for S =1/2 with intraplanar exchange constants J 1 =2.01 meV, J 2 =0.019 meV and J 3 =-0.338 meV, interplanar exchange J '=-0.97 meV, and planar anisotropies D 1 =1.14 meV and D '=-0.06 meV. As shown by these numerical values, CoBr 2 has fairly strong XY characters, but the two-dimensionality is definitely poor. We point out, however, that in a planar antiferromagnet, the easy plane type anisotropy should remove the degeneracy of the excitation spectrum for the `in-plane' and the `out-of-plane' correlations, and in fact, these excitations are observed separately in this experiment.","PeriodicalId":269857,"journal":{"name":"Tokyo Sugaku Kaisya Zasshi","volume":"14 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1980-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"23","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tokyo Sugaku Kaisya Zasshi","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1143/JPSJ.48.42","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 23
Abstract
In order to investigate the two-dimensionality and the easy plane anisotropy, the spin waves propagating along the [h, 0, 0], [h, h, 0], [h, 0.5h, 0] and [0, 0, l ] directions in CoBr 2 were observed using inelastic neutron scattering technique. The spin dynamics of CoBr 2 can be described by the anisotropic exchange Hamiltonian for S =1/2 with intraplanar exchange constants J 1 =2.01 meV, J 2 =0.019 meV and J 3 =-0.338 meV, interplanar exchange J '=-0.97 meV, and planar anisotropies D 1 =1.14 meV and D '=-0.06 meV. As shown by these numerical values, CoBr 2 has fairly strong XY characters, but the two-dimensionality is definitely poor. We point out, however, that in a planar antiferromagnet, the easy plane type anisotropy should remove the degeneracy of the excitation spectrum for the `in-plane' and the `out-of-plane' correlations, and in fact, these excitations are observed separately in this experiment.