Pressure Effects on Molecular Magnets of Mn Complexes with Bisaminoxylbenzene Derivatives

Abstract

Pressure effects on the magnetic properties of a series of quasi-one-dimensional molecular magnets have been studied. The complexes of Mn(hfac) 2 (hfac = hexafluoroacethylacetonate) with 1,3-bis( N-tert -buthylaminoxy)benzene and it's 5-halo- derivatives, abbreviated as 1 x (X = H, F, Cl and Br), have almost the same ferrimagnetic chain structure. The difference is seen in the interchain molecular arrangement. The complexes of 1 H and 1 F are metamagnets with weak interchain antiferromagnetic interactions, whereas 1 Cl and 1 Br are ferrimagnets with weak interchain ferromagnetic interactions. In two metamagnets ( 1 H , 1 F ), the pressurization simply results in the enhancement of the interchain antiferromagnetic interactions, which is reflected by the higher transition temperature and spin-flipping field. On the other hand, in the ferrimagnet ( 1 Cl ) the metamagnetic behavior is observed under pressure. It is suggested that the subtle change of the relative arrangement of chain structures affects the interchain ferromagnetic interactions. Molecular magnet quasi-one-dimensional magnet metamagnetism ferrimagnetism pressure effect aminoxyl radical