Among several class of molecule-based metal assembled magnetic materials, quasi 2D materials of general molecular formula A[M(II)M(III)(C2O4)3] - first reported by Hisashi Ōkawa and his group of Japan in 1990 had drawn much interest in the field of molecule-based magnetic materials research. Depending upon the metal ion combinations the nature of magnetic interactions observed are ferro-/ferri-/antiferro-/paramagnetism. The counter cation ‘A’ has been found to play a crucial role in observing phenomenon like spin-glass and rarely occurring magnetic compensation effect. Studies on the low temperature magnetic property of these complexes have always remained challenging. Recently, interesting studies on the synthesis of various ‘atom-based’ magnetic materials on thermal decomposition of ‘molecule-based’ A[M(II)M(III)(C2O4)3] have been reported. Thus, A[M(II)M(III)(C2O4)3] type materials starting journey in 1990 remains relevant in the field of materials science research even after three decades. The present article introduces the A[M(II)M(III)(C2O4)3] type materials, reviews the studies on their interesting magnetic property made throughout the three decades and discusses the scopes of using these materials for the synthesis of various homo/heterometallic magnetic materials in the field of materials science research.
Keywords: Molecule based magnets, metal-assembled materials, oxalate ligand based magnets, magnetic interactions, compensation effect, mixed-metal assembly, spin-glass, thermal decomposition, synthesis of ferrites.