Saturation Field of Frustrated Chain Cuprates: Broad Regions of Predominant Interchain Coupling

S. Nishimoto,
S.-L. Drechsler,
J. van den Brink,
J. Richter,
W. E. A. Lorenz,
Y. Skourski,
R. Klingeler,
B. Büchner

Інститут проблем матеріалознавства ім. І. М. Францевича НАН України , вул. Кржижановського 3, Київ, 03142, Україна
Phys. Rev. Lett. - Меріленд, США: Американське Фізичне Суспільство (APS), 2011, #107


A thermodynamic method to extract the interchain coupling (IC) of spatially anisotropic 2D or 3D spin-1/2 systems from their empirical saturation field Hs (T=0) is proposed. Using modern theoretical methods we study how Hs is affected by an antiferromagnetic (AFM) IC between frustrated chains described in the J1-J2-spin model with ferromagnetic 1st and AFM 2nd neighbor in-chain exchange. A complex 3D-phase diagram has been found. For Li2CuO2 and Ca2Y2Cu5O10, we show that Hs is solely determined by the IC and predict Hs≈61 T for the latter. With Hs≈55 T from magnetization data one reads out a weak IC for Li2CuO2 close to that obtained from inelastic neutron scattering.