Fe-gluconate: Insights from magnetometry

Abstract

Magnetic measurements of three forms of Fe-gluconate (hydrated, anhydrous and amorphous) have been performed. Both molar susceptibility in the temperature interval of 2–300 K as well as isothermal magnetization at 2 K were registered. A two-stage analysis was performed. The first stage assumes a single ferrous and a single ferric component, while in the second stage an additional ferrous component is considered. The initial results implied the need to rescale the molar masses of the studied samples and both stages were recalculated with the appropriate rescaling. This step made the values of the spectroscopic factors of the ferrous components more physically plausible without a substantial modification of the remaining parameters. The ferrous fractions found in the analysis mostly exceed those revealed by the Mössbauer spectroscopy, hence smaller ferric fractions are predicted: 23(8)%, 9(3)%, and 15(1)% for the hydrated, anhydrous and amorphous sample, respectively. Some qualitative insight into the magnetic anisotropy of the constituent ions is provided implying low coordination numbers for the Fe(II) ions.