Tuning the magnetic properties in the layered molecular based magnets A[(FeRuxM1-xIII)-Ru-II-M-III(ox)(3)] (M-III = Cr or Fe; ox = oxalate; A = organic or organometallic cation)

The magnetic properties of the family of layered molecular magnets A[(FeMnI II)-Mn-II(ox)(3)] (M-III = Cr, Fe, Ru; ox = oxalate; A(+) = [NBu4](+), [CoC p2*](+)) are reported. In particular, a detailed magnetic study of the soli d solutions Fe-II((RuCrIII)-Cr-III) and Fe-II((RuFeIII)-Fe-III) has been un dertaken. We show that in these magnets both, transition temperatures and c oercive 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 magn etic layers and the type of cation A(+) inserted in between the layers. Coe rcive fields as high as 2.2 T have been reached in this way. (C) 2001 Elsev ier Science B.V. All rights reserved.