Physics

  2010 MAR 23 - (VerticalNews.com) -- "Crystal structure and magnetic properties of the Pr0.5Sr0.5Co1-xFexO3-d are studied to clarify an origin of the magnetic peculiarity observed for Pr0.5Sr0.5CoO3-d compound near T-A approximate to 120 K. A correlation between crystal symmetry, magnetic structure, and the magnetic anomaly is discussed. At room temperature the compounds with x< 0.67 have orthorhombic crystal structure described by Imma space group," scientists in Aveiro, Portugal report ...read more

  2010 MAR 23 - (VerticalNews.com) -- "Polarized reflectivity spectra of PbMoO4 crystals have been measured using synchrotron radiation up to 20 eV. The optical constants for the crystallographic axes are derived by using a Kramers-Kronig analysis," scientists in Kure, Japan report.

  "It is found that the exciton band at 3.6eV shows a doublet structure with distinct dichroism X-ray photoemission spectroscopy (XPS) and the calculation of the electronic spectroscopy (XPS) and the calculation of the electronic structure by a discrete variational X alpha method are also carried out. The calculation shows that the valence band and the conduction band are mainly composed of the O 2p and Mo 4d states, respectively, and the Pb state contributes appreciably to the top of the valence band and the bottom of the conduction band. The valence-band XPS spectrum of PbMoO4 is compared with that of PbWO4, which reveals a remarkable difference between them. This difference reflects different magnitudes of hybridization of Mo 4d or W 5d state to the valence band. The exciton transition is explained in terms of the cationic Pb 6s -> 6p excitation model taking into account the crystal-field splitting and the spin-orbit interaction of Pb 6p state. From a comparison of the doublet structure of the exciton band of PbMoO4 and PbWO4," wrote M. Fujita and colleagues, Coast Guard ...read more

  2010 MAR 23 - (VerticalNews.com) -- According to recent research from Nanjing, People's Republic of China, "Camley and Barnas (CB) model was improved by taking into consideration of the interface scattering and bulk spin-flip effect."

  "The comparison between model's prediction and experimental data shows that the spin-flip effect plays an indispensable role in affecting the MR of spin valves. The electron spin specular reflectivity at the interface of NiO/Co in NiO-containing Co/Cu/Co spin valves is determined using the improved CB model, which varies with the structural configuration and the annealing temperature," wrote A.M. Zhang and colleagues, NanJing University ...read more