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The surface electronic structure of 1500-angstrom-thick Fe3O4(100) films is investigated by spin0-resolved photoemission spectroscopy with vacuum ultraviolet synchrotron radiation. The top of the valence band is found to be negatively spin polarized, with a value of approximately -50 percent, thus pointing towards the localized nature of the 3d states in the system.

Investigates the possibility of a transmission-type X-ray linear polarizer using a thin Bragg reflector as a polarizing filter. Transmitted beam as the useful output of the device; Changes in the position and direction of the transmitted beam as the energy is changed; Use of perfect crystals of silicon and diamond.

The National Synchrotron Light Source (NSLS) 2.8 GeV electron storage ring continues to set high standards in insertion-device research and development. The Chasman-Green NSLS lattice design provides for dispersion-free long straight sections in addition to a very small vertical β function. As the electron beam size is proportional to the square root of this function, a program to exploit this feature was undertaken more than a decade ago by implementing short-period small-gap insertion devices in the NSLS storage ring. The possibility of utilizing existing moderate-energy synchrotron radiation electron storage rings to produce high-brightness photon beams into the harder X-ray region have been realised using in-vacuum undulators. In this article the operation of a 1.25 cmperiod mini-gap undulator, operating down to a gap of 3.3 mm within the NSLS X13 straight section, is reported. It is the brightest source of hard X-rays in the energy range ∼3.7-16 kev at the NSLS, and replaces an in-vacuum undulator which had a more limited tunability. [ABSTRACT FROM AUTHOR]