Spin transitions in ferropericlase under high pressure: Comparison of Mossbauer-spectroscopy and X-ray emission-spectroscopy data

The spin state of iron in ferropericlase, and parameters of the spin transition, is investigated. The methods used included absorption-spectrum measurements in the optical and near infrared ranges, and Mössbauer spectroscopy. In the XES analysis, intensities of all spectra were normalized to the maximum of the main Kβ peak and all spectra were shifted along the abscissa axis to make coincident the positions of the main K β peak. The spectrum corresponding to the highest pressure was subtracted from the remaining spectra and for the difference spectra, the area under the Kβ peak was measured and normalized to the value corresponding to zero pressure. The iron Kβ spectrum consisted of a main asymmetric peak near 7058 eV and a weak peak near 7044 eV, denoted as Kβ. The XES analysis made it possible to reach the quantitative agreement with the Mössbauer spectroscopy data.