Two-magnon Raman scattering from the Cu3O4 layers in (Sr-2,Ba-2)Cu3O4Cl2
2009 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 79, no 8, 085109- p.Article in journal (Refereed) Published
(Sr-2,Ba-2)Cu3O4Cl2 are antiferromagnetic insulators which are akin to the parent compounds of the cuprate superconductors but with two distinct magnetic ordering temperatures related to two magnetic Cu-I and Cu-II spin sublattices. Here we present a study of these materials by means of Raman spectroscopy. Following the temperature and polarization dependence of the data, we readily identify two distinct features at around 3000 and 300 cm(-1) that are related to two-magnon scattering from the two sublattices. The estimated spin-exchange coupling constants for the Cu-I and Cu-II sublattices are found to be J(I)similar to 139-143(132-136) meV and J(II)similar to 14 (11) meV for Sr(Ba) compounds. Moreover, we observe modes at around 480 and 445 cm(-1) for the Sr and Ba containing samples, respectively, which disappears at the ordering temperature of the Cu-II. We argue that these modes may also be of magnetic origin and possibly related to interband transitions between the Cu-I-Cu-II sublattices.
Place, publisher, year, edition, pages
2009. Vol. 79, no 8, 085109- p.
antiferromagnetic materials, barium compounds, exchange interactions (electron), high-temperature superconductors, magnetic superconductors, magnons, Raman spectra, strontium compounds
IdentifiersURN: urn:nbn:se:uu:diva-129935DOI: 10.1103/PhysRevB.79.085109ISI: 000263816000022OAI: oai:DiVA.org:uu-129935DiVA: diva2:345607