We present experimental evidence for the existence of interlayer states formed in graphite-sulfur ͑C-S͒ composites. We have studied occupied and unoccupied p bands of the C-S composites by means of soft x-ray absorption and emission spectroscopy. New spectral features in the C 1s absorption are interpreted as contributions arising from the interaction of sulfur s states with graphite interlayer states. The equivalence of C K␣ x-ray emission spectra of C-S and graphite lets us conclude that the interlayer states are entirely located above the Fermi level.

The electronic structure of Cu hexafluoroacetylacetonate, crystallized with a stable nitronyl nitroxide radical [Ovcharenko et al., Russ. Chem. Bull. 53, 2406], is calculated from first principles within the density functional theory using the SIESTA method, in two magnetic configurations reflecting parallel or antiparallel setting of S = 1/2 spins of Cu(II) ions to those of organic radicals. For a given (high-temperature) crystal structure, the interaction is found to be predominanty antiferromagnetic, and its magnitude estimated to be 67 cm −1 . This preference is discussed in terms of calculated electronic properties (densities of states, molecular orbitals).

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The temperature-dependent Verwey transition in a 500 Å (111) thin film of Fe3O4 (magnetite) has been studied using soft-x-ray emission spectroscopy at room temperature and below the transition temperature TV. The Fe L2,3 x-ray emission spectra show an increase in the intensity of the L2 emission relative to the L3 emission below TV. This is independent of the excitation energy and is attributed to a metal–insulator transition across TV. Comparison of the Fe L3 emission and O Kα spectra with LDA band structure calculations supports the suggestion of charge ordering in Fe3O4 at low temperature.