Comparative investigation of the coupled-tetrahedra quantum spin systems Cu2Te2O5X2, X=Cl, Br and Cu4Te5O12Cl4

Abstract

We present a comparative study of the coupled-tetrahedra quantum spin systems Cu2Te2O5X2, X=Cl, Br (Cu-2252(X)) and the newly synthesized Cu4Te5O12Cl4 (Cu-45124(Cl)) based on ab initio Density Functional Theory calculations. The magnetic behavior of Cu-45124(Cl) with a phase transition to an ordered state at a lower critical temperature T${}_c$=13.6K than in Cu-2252(Cl) (T${}_c$=18K) can be well understood in terms of the modified interaction paths. We identify the relevant structural changes between the two systems and discuss the hypothetical behavior of the not yet synthesized Cu-45124(Br) with an ab initio relaxed structure using Car-Parrinello Molecular Dynamics.

arXiv comment2 pages, 1 figure; submitted to Proceedings of M2S-HTSC VIII, Dresden 2006

References in corpus (7)

• Muffin Tin Orbitals of Arbitrary Order
• Evidence for an unconventional magnetic instability in the spin-tetrahedra system Cu_2Te_2O_5Br_2
• Longitudinal magnon in the tetrahedral spin system Cu2Te2O5Br2 near quantum criticality
• Halogen-mediated exchange in the coupled-tetrahedra quantum spin systems Cu2Te2O5X2 (X=Br,Cl)
• Incommensurate magnetic ordering in $C{u}_{2}T{e}_2{O}_5{X}_2$ (X=Cl,Br) studied by neutron diffraction
• Incommensurate magnetic ordering in Cu2Te2O5X2 (X=Cl, Br) studied by single crystal neutron diffraction
• Microscopic model for the novel frustrated Cu(II)-spin tetrahedron-based Cu4Te5O12X4 (X=Cl, Br) systems