High magnetic field induced spin transition, HMFIST effect, in [Fe0.52Ni0.48(btr)(2)(NCS)(2)]H2O

We report the effect of a high magnetic field (30 T) on the LS <-> HS trans ition in [Fe0.52Ni0.48(btr)(2)(NCS)(2)]H2O. We have developed a new experim ental set-up which allows to determine under a high pulsed magnetic field, the proportion n(HS) of molecules in the high spin state (S = 2). The exper iments, performed under quasi-static pulsed field, are based on the optical reflectivity as detection of the LS <-> HS transition. The results on [Fe0 .52Ni0.48(btr)(2)(NCS)(2)]H2O are: reported and show that a partial spin tr ansition (10%) may be induced by using a pulse of 30 T and confirm the prev ious study of Fe(Phen)(2)(NCS)(2). (C) 2000 Elsevier Science S.A. All right s reserved.