Valence states of iron ions in nanostructured yttrium iron garnet Y3FE5O12 studied by means of soft X-ray absorption spectroscopy

Nanostructured samples of yttrium iron garnet Y3Fe5O12 obtained by plastic deformation method (high-pressure torsion) were studied with help of soft X-ray absorption spectroscopy using Fe 2p and O 1s spectra. Experimental spectra were compared with crystal field multiplet calculations for Fe ions. Some amount of Fe2+ ions in nanostructured Y3Fe5O12 was found. The concentration of Fe2+ ions was found to be increased with the increase of the degree of plastic deformatio

Electronic structure of molecular superconductors containing paramagnetic 3d ions

The results of x-ray fluorescence measurements of the molecular superconductors (ET)[(HO)Fe(CO) ]·CHCN (T = 8.5 K) and (ET)[(HO)Cr(CO) ]·CHCN (T ∼ 6 K) and molecular conductor (ET)[(HO)Fe(CO) ]·CHN containing paramagnetic 3d ions are presented. The following transition of the x-ray emission valence spectra are monitored: C K α, N K α (2p→1s transition) and Fe L, Cr L (3d4s→2p transition). It is found that the electronic structure of the solvents (benzonitrile, pyridine) that occupy the hexagonal cavities formed by the anionic layer is close to that of the neutral molecule. The ratio of the emission intensities of the peaks L to L for Fe and Cr is found to be 2.8-3.1 times higher for (ET)[(HO)Fe(CO) ]·CHCN and (ET)[(HO)Cr(CO) ]·CHCN than for pure metals. This indicates that the paramagnetic 3d ions are situated in highly insulating anionic layers. We did not find any changes in the C K α emission for different solvent molecules

Electronic structure of molecular superconductors containing paramagnetic 3d ions

The results of x-ray fluorescence measurements of the molecular superconductors (ET)[(HO)Fe(CO) ]·CHCN (T = 8.5 K) and (ET)[(HO)Cr(CO) ]·CHCN (T ∼ 6 K) and molecular conductor (ET)[(HO)Fe(CO) ]·CHN containing paramagnetic 3d ions are presented. The following transition of the x-ray emission valence spectra are monitored: C K α, N K α (2p→1s transition) and Fe L, Cr L (3d4s→2p transition). It is found that the electronic structure of the solvents (benzonitrile, pyridine) that occupy the hexagonal cavities formed by the anionic layer is close to that of the neutral molecule. The ratio of the emission intensities of the peaks L to L for Fe and Cr is found to be 2.8-3.1 times higher for (ET)[(HO)Fe(CO) ]·CHCN and (ET)[(HO)Cr(CO) ]·CHCN than for pure metals. This indicates that the paramagnetic 3d ions are situated in highly insulating anionic layers. We did not find any changes in the C K α emission for different solvent molecules

X-ray emission, photoelectron spectra, and electronic structure of Sr2CuO2F2+ delta.

The electronic structure of the high-Tc superconductor Sr2CuO2F2+ has been investigated by means of x-ray-emission spectroscopy (O K, Cu L F K), x-ray-photoelectron spectroscopy, and band-structure calculations using the full-potential linear muffin-tin orbital method. The local environment of the F atoms and the valence state of the Cu atoms in Sr2CuO2F2+ are discussed. On the basis of the x-ray-photoelectron and x-ray-emission spectra it is concluded that the F atoms preferentially bond to Sr atoms in this compound. © 1995 The American Physical Society

Co 3d-level position in ZnS : Co semiconductors

Experimental studies of x-ray photoelectron and Co Lalpha x-ray emission spectra of the ZnS:Co semiconductor were carried out. It was established that Co ions are present in isovalent Co2+ configuration and that the Co 3d impurity states are localized above the top of the valence band by 1.0 +/- 0.2 eV