Two-magnon Raman scattering from the Cu3O4 layers in (Sr-2,Ba-2)Cu3O4Cl
Artikel i vetenskaplig tidskrift, 2009

(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.

Raman spectra

exchange interactions (electron)

barium compounds

high-temperature superconductors


magnetic superconductors

strontium compounds

antiferromagnetic materials


Joakim Holmlund

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Christopher Knee

Göteborgs universitet

Jakob Andreasson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Mats Granath

Göteborgs universitet

Alexander Litvinchuk

Lars Börjesson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Physical Review B - Condensed Matter and Materials Physics

24699950 (ISSN) 24699969 (eISSN)

Vol. 79 8 85109-



Övrig annan teknik

Annan materialteknik

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