Tuning the magnetic properties in the layered molecular based magnets A[FeIIRuxIIIM1-xIII(ox)3] (MIII = Cr or Fe;: ox = oxalate;: A = organic or organometallic cation)

The magnetic properties of the family of layered molecular magnets A[(FeMnIII)-Mn-II(ox)(3)] (M-III = Cr, Fe, Ru; ox = oxalate; A(+) = [NBu4](+), [CoCp2*](+)) are reported. In particular, a detailed magnetic study of the solid solutions Fe-II((RuCrIII)-Cr-III) and Fe-II((RuFeIII)-Fe-III) has been undertaken. We show that in these magnets both, transition temperatures and coercive fields, can be easily tuned by changing the chemical composition of the material, i.e. the ratio Ru-III/M-III (M-III = Cr, Fe) within the magnetic layers and the type of cation A(+) inserted in between the layers. Coercive fields as high as 2.2 T have been reached in this way. (C) 2001 Elsevier Science B.V. All rights reserved.