Magnetic dilution effect on the charge transfer phase transition and the ferromagnetic transition for an iron mixed-valence complex, (n-C3H7)4N[FeII1−xZnIIxFeIII(dto)3] (dto = C2O2S2)

Iron mixed-valence complex, (n-C3H7)4N[FeIIFeIII(dto)3] (dto = C2O2S2) shows a new-type of phase transition coupled with spin and charge around 120 K, where the charge transfer between the FeII and FeIII sites occurs reversibly, and shows the ferromagnetic transition at 7 K. To investigate the magnetic structure and its dimensionality of (n-C3H7)4N[FeIIFeIII(dto)3], we have synthesized a mixed crystal system, (n-C3H7)4N[FeII1−xZnIIxFeIII(dto)3], and measured its magnetic properties. In this system, the magnetic moment is reduced with increasing of Zn ratio. Moreover, the ferromagnetic interaction changes to the antiferromagnetic one and the remnant magnetization disappears between x = 0.48 and 0.96, while the charge transfer between the FeII and FeIII sites disappears above x = 0.26. In this paper, we present the magnetic dilution effect on the charge transfer phase transition and the ferromagnetic transition by means of magnetic susceptibility measurement and 57Fe Mössbauer spectroscopy.

Graphical abstractAn magnetic diluted complex, (n-C3H7)4N[FeII1−xZnIIxFeIII(dto)3] (dto = C2O2S2) was synthesized and measured its magnetic properties in order to investigate the magnetic structure of (n-C3H7)4N[FeIIFeIII(dto)3], whose magnetic transition is coupled with charge transfer between adjacent iron sites. In this system, the charge transfer phase transition disappears above x = 0.26, while the ferromagnetic interaction changes to the antiferromagnetic one between x = 0.48 and 0.96.Figure optionsDownload full-size imageDownload as PowerPoint slide