Antiferromagnetic interactions in a distorted cubane-type tetranuclear manganese cluster

Abstract

We have synthesized a new tetranuclear manganese cluster with a distorted cubanelike [Mn4O4]-core. High field magnetization experiments reveal an intramolecular antiferromagnetic coupling between the four manganese ions. We explain our results both qualitatively and quantitatively by a simple spin square model in terms of four equal antiferromagnetic exchange interactions in the core with coupling strengths of J =-1.69 K.

Padé approximations for the magnetic susceptibilities of Heisenberg antiferromagnetic spin chains for various spin values

“…In this paper we report the simulated spin susceptibility of the S = 1, 3 2 , 2, 5 2 and 7 2 Heisenberg antiferromagnetic nearest-neighbor spin chain, in the temperature range of 0.005 ≤ k B T J NN ≤ 100. The simulations were fitted to a modified PA, which was subsequently tested against experimental results in order to extract the intra-chain spin exchange interactions and the g-factor.…”

“…Generally, the results of such simulations are only available as tabulated data and thus difficult to compare with experiments. On the other hand, the analysis of temperature and/or field dependent observables and the comparison with model calculations has become a powerful tool for understanding and analyzing the spin-exchange interactions (SEI) in new low-dimensional quantum antiferromagnets [1][2][3][4][5][6][7]. Johnston et al showed that the magnetic susceptibility and the heat capacity of an S = 1/2 Heisenberg antiferromagnetic chain (HAFC), with both uniform and alternating SEI, which had been simulated by using quantum Monte Carlo (QMC) and transfer-matrix density-matrix renormalization group calculations, can be fitted with Padé approximations (PA) to a very high precision, enabling detailed and easy comparison with experimental findings [8,9].…”