Pressure effect on Mn complexes of bisaminoxyl radicals

The pressure effects on magnetic properties of one-dimensional Mn complexes with 1,3-bis(N-tert-butylaminoxyl)benzene and 5-chloro-1,3-bis(N-tert-buty laminoxyl)be have been studied. These complexes have weak interchain intera ctions with different signs and the former is a metamagnet and the latter i s a ferrimagnet at ambient pressure. The interchain interactions of the for mer is enhanced by pressurization. The transition temperature becomes highe r and the critical field becomes larger with applying pressure. The closer spacing of each chains caused by pressurization, yields larger antiferromag netic interchain interactions in this compound. On the other hand, the resp onse to the pressure of the latter ferrimagnet, is rather complicated. The transition temperature becomes higher and the antiferromagnetic interchain interactions are induced by pressurization. The interchain exchange couplin g in this compound should be sensitive to the relative orientation of the c hain structure. The decrease of the ferromagnetic contribution and/or the i ncrease of the antiferromagnetic one in the interchain interactions is brou ght about by pressurization.