High-field magnetization of V15 cluster at ultra-low temperatures:: Importance of antisymmetric exchange and its precise estimation

The low temperature adiabatic magnetization of the nanoscopic V-15 cluster exhibiting a triangular spin-frustrated V-3(IV) array is analyzed within the model that includes isotropic exchange interactions and antisymmetric (AS) exchange. Along with the absolute value of AS exchange the orientation of the AS vector is shown to play an important physical role in the spin-frustrated systems. We were able to reach a perfect tit to the experimental data on the stepwise magnetization vs. field in the whole temperature range and for the first time to estimate precisely two components of the AS vector, namely, in-plane and the perpendicular parts. (c) 2006 Elsevier B.V. All rights reserved.