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A study was conducted to analyze expressions for the resonant magnetic x-ray scattering from rough surfaces. Four formulas were utilized to examine the structural and magnetic roughness, including the correlation between them. The effects of magnetic domain structure and magnetic dead layers on the surface scattering was then discussed. Experimental results indicated that the leading contribution to the diffuse component is nonzero if the magnetic and structural roughness are correlated.

Systematic temperature dependent magnetic extended x-ray absorption spectroscopy (MEXAFS) measurements are presented, with the fine structure explained by the spin dependent photoelectron scattering. Information is provided about the local magnetic surroundings of the absorbing atom. Strong temperature dependence was found at temperatures way below the Curie temperature, indicating that the intensity of the MEXAFS signal is also determined by relative vibrations of a backscattering atom to an absorbing atom.

A study of thin CoFe films where increased chemical roughness was induced by the growth process, has been undertaken to give a better understanding of the variation of magnetic versus chemical interfaces. Results show that the chemical and magnetic interfaces behave differently as the root mean square chemical roughness is increased. Variations in the magnetic diffuse intensity are also demonstrated as possible probes of interfacial magnetic hysteresis.

The spin wave spectrum at the Fe(100)/NM(111) interface of a multilayer noble metal (NM) interlayer is determined using surface-sensitive Mossbauer spectroscopy. A Bloch law describes the temperature dependence of the hyperfine field. The surface spin-wave stiffness parameter is linked with the interlayer exchange coupling by spin wave calculations.

Element-sensitive x-ray resonant magnetic scattering is used for measuring layer-resolved magnetic hysteresis loops on a periodic square frame nanostructure. The layer- and spatially resolved magnetic measurements have disclosed distinct magnetic reversal mechanisms in different regions due to interplay between the shape anisotropy and interlayer dipolar coupling.

The demagnetization protocols for frustrated arrays of interacting single-domain permalloy nanomagnets are studied by rotating the arrays in a changing magnetic field. The results have shown that nonmonotonic variations in field magnitude around and below the coercive field are vital for demagnetization process.

Fe/Sm-Co bilayers are fabricated with gradient Fe thickness in order to systematically study the dependence of exchange coupling on the thickness of the Fe layer. The Fe layer is deposited at two different temperatures (150 and 300 degree Celsius) to study the effect of deposition temperature on exchange coupling.

Synchrotron-radiation glancing-incidence and angle-resolved photo electron spectroscopy (PES) is used to study the oxides grown in air on a single-crystal Nab (100) surface. Both core-level and valance-band PES are measured for various heat treatments.

The extraction of domain-specific magnetization reversals from soft x-ray resonant magnetic scattering measurements on a Permalloy square ring array is discussed. It was observed that the magnetization of the domain parallel to the field is strongly pinned and the magnetization of other domains rotate continuously.

Examines the magnetic roughness of cobalt and ireon (CoFe) thin films. How diffuse x-ray resonant magnetic scattering was used to investigate the magnetic roughness of these films; Information on magnetic interfaces; In-depth look at the behavior of the chemical versus magnetic interfaces when chemical roughness is increased.

The electronic structure of transition metal oxides featuring correlated electrons can be rationalized within the Zaanen-Sawatzky-Allen framework. Following a brief description of the present paradigms of electronic behavior, we focus on the physics of rare-earth nickelates as an archetype of complexity emerging within the charge transfer regime. The intriguing prospect of realizing the physics of high- Tc cuprates through heterostructuring resulted in a massive endeavor to epitaxially stabilize these materials in ultrathin form. A plethora of new phenomena unfolded in such artificial structures due to the effect of epitaxial strain, quantum confinement, and interfacial charge transfer. Here we review the present status of artificial rare-earth nickelates in an effort to uncover the interconnection between the electronic and magnetic behavior and the underlying crystal structure. We conclude by discussing future directions to disentangle the puzzle regarding the origin of the metal-insulator transition, the role of oxygen holes, and the true nature of the antiferromagnetic spin configuration in the ultrathin limit. [ABSTRACT FROM AUTHOR]

Interlayer coupling in epitaxial Fe(110)/Ag(111) multilayered structures grown by molecular beam epitaxy was investigated using x-ray diffraction and Mossbauer spectroscopy. The results showed that the samples were single-crystalline and well-oriented with no detected Bragg reflections. The spin wave spectrum of the films softened as the Ag interlayer thickness was increased.

Determines the order of layer switching in a nitrogen iron/copper/cobalt spin valve using circular polarized x-ray resonant magnetic scattering (XRMS). Significance of the separated ferromagnetic layers by nonmagnetic spacers; Demonstration of the utility of circularly polarized XRMS.

Site-selective luminescence experiments were performed upon porous-silicon samples exposed to varying degrees of oxidation. The source of different luminescence bands was determined to be due to either quantum confinement in nanocrystalline silicon or defective silicon oxide. Of particular interest is the defective silicon-oxide luminescence band found at 2.1 eV, which was found to frequently overlap with a luminescence band from nanocrystalline silicon. Some of the historical confusion and debate with regards to the source of luminescence from porous silicon can be attributed to this overlap. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Through a direct study of the chemical and magnetic interfacial disorder in conjunction with magnetic property measurements, evidence is presented that the grain size is the ultimate factor in determining the magnetic coercivity in CoFe thin film structures. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: Photoluminescence from Alq3 (tris-aluminum-8-hydroxyquinolinate) excited with synchrotron light in both the UV (5 –20eV) and the soft X-ray (Al K-edge) region are reported and are compared with results with excitation at the K-edge energies of C, N and O. X-ray emission excited with photon energy above the carbon and the nitrogen K-edge are also reported. It is found that the luminescence is sensitive to the excitation channel and can be interpreted in terms of the C and N K-edge X-ray absorption near edge structures (XANES) and X-ray emission spectroscopy (XES) results as well as a recent theoretical calculation. [Copyright &y& Elsevier]