In Part 2 of this work, the electronic and local structure of the photoinduced metastable magnetic state of the Prussian blue analogue Rb1.8Co4[Fe(CN)6]3.3·13H2O were characterized. To determine directly the relative orientation of the magnetic moments of CoII and FeIII ions in the metastable state, and the nature of the exchange interaction between them, we performed X-ray magnetic circular dichroism (XMCD) experiments at the cobalt and iron K edges. We present the first direct experimental evidence of the antiferromagnetic interaction between the cobalt and the iron ions, leading to the ferrimagnetism of the photoinduced metastable state.

The synthesis and the magnetic properties of two new bimetallic chromium-vanadium ferrimagnets, compounds 1 and 2, are reported. They belong to a set of nonstoichiometric Prussian blue analogues C I y V-[Cr III (CN) 6 ] z ‚nH 2 O (C, alkali cation) with T C varying between 295 and 315 K (T C ) 310 K for 1 and 315 K for 2). They are obtained through mild chemistry from the molecular precursor [Cr III (CN) 6 ] 3and from vanadium V II salts. The synthetic conditions determine (i) the oxidation state of the vanadium (V II , V III , or V IV ), (ii) the stoichiometry, and (iii) hence the magnetic properties. The reported systems present a larger magnetization than the first reported V-Cr analogue (0.36N A β for 1 and 0.40N A β for 2). Furthermore, X-ray magnetic circular dichroism (XMCD) data demonstrate (i) the short-range antiferromagnetic coupling between the spins borne by the chromium(III) and vanadium ions and (ii) the reversal of the local magnetization on vanadium and chromium when changing the stoichiometry.