Two-magnon Raman scattering from the Cu3O4 layers in (Sr,Ba)2Cu3O4Cl2

Abstract

(Sr${}_2$,Ba${}_2$)Cu${}_3$O${}_4$Cl${}_2$ 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 cm${}^{-1}$ 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\sim$139-143(132-136) meV and J${}_{II}\sim$14(11) meV for Sr(Ba) compounds. Moreover, we observe modes at around 480 and 445 cm${}^{-1}$ for the Sr and Ba containing samples respectively, that disappears at the ordering temperature of the Cu${}_{II}$. We argue that this modes may also be of magnetic origin and possibly related to interband transitions between the Cu${}_I$-Cu${}_{II}$ sublattices.

arXiv comment7 pages, 8 figures

References in corpus (7)

• Resonant two-magnon Raman scattering in parent compounds of high-T${}_c$ superconductors.
• Resonant two-magnon Raman scattering in antiferromagnetic insulators
• Resonant Two-Magnon Raman Scattering in Cuprate Antiferromagnetic Insulators
• Neutron Scattering study of Sr_2Cu_3O_4Cl_2
• Tight-binding parameters and exchange integrals of Ba_2Cu_3O_4Cl_2
• Raman scattering in a two-layer antiferromagnet
• Neutron Scattering and magnetization studies of Ba${}_2$Cu${}_{2.95}$Co${}_{0.05}$O${}_4$Cl${}_2$: A decorated two-dimensional antiferromagnet

Cited by in corpus (2)

• Highly dispersive magnons with spin-gap like features in the frustrated ferromagnetic S=1/2 chain compound Ca2Y2Cu5O10 detected by inelastic neutron scattering
• Thermal Conductivity due to Spins in the Two-Dimensional Spin System Ba${}_2$Cu${}_3$O${}_4$Cl${}_2$