Current driven magnetization reversal in microstructured spin valve with current-in-plane configuration J. Appl. Phys. 105, 07D118 (2009); 10.1063/1.3068483Effect of polarized current on the exchange bias in a current-in-plane spin valve Exchange-biasing asymmetric spin valves using a pulsed current

Isothermal constant-displacement-rate compression tests of superalloy IN718 were conducted using a computer-controlled MTS machine, at temperatures from 960 ЊC to 1040 ЊC, initial strain rates from 0.001 to 1.0 s Ϫ1 , and true strains from 0.105 to 1.204 (corresponding to a relative height reduction from 10 to 70 pct). The flow stress was obtained directly from compression tests using the controlling computer. The grain size was obtained by the intercept method and by comparing microstructures to the ASTM standard grain chart. Based on the results of these tests, a mathematical model showing the hot-deformation behavior of superalloy IN718 was developed in the form of a constitutive equation and a Hall-Petch relationship. Both the flow stress and the grain size calculated from the model were compared to the experimental results. Meanwhile, the effect of hot-deformation parameters such as strain, strain rate, and temperature on the flow stress and on the grain size was analyzed according to the model. It was found that these parameters influenced the flow stress and the grain size. The model developed in this work can be used to explain such effects.

Broadband extreme ultraviolet molybdenum/yttrium aperiodic multilayer analyzers were designed for polarization experiments in 8.5-11.7 nm wavelength range. The multilayer analyzers were made using direct current magnetron sputtering and characterized using the soft x-ray polarimeter at BESSY-II facility. Measured s reflectivities at the Brewster angle are 5.5% for a multilayer designed for 8.5-10.1 nm wavelength range and 6.1% for one designed for 9.1-11.7 nm. The multilayers also exhibit high polarization degree up to 98.79%. In addition, the multilayer was also measured over 38°-52°angular range at the fixed wavelength of 10.2 nm and the mean s reflectivity is 6.2%.

The possibility of obtaining edge states of light that are robust against disorder by mimicking the topological properties of a solid-state system has brought a profound impact on optical sciences. In the short-wavelength region, X-ray science and technology is undergoing tremendous development. It requires high-precision optics with exquisite control of light properties and robustness against structural perturbations. Therefore, it is very attractive to extend the concept of optical topological manipulation to the X-ray regime. Herein, the topological edge state is theoretically proposed and experimentally demonstrated at the interface of two kinds of photonic crystals having different bandgap topological characteristics in the X-ray regime. Remarkably, this topologically protected edge state is immune to the thickness disorder as long as the zero-average-effective-mass condition is satisfied. This work extends the topological photonics to the X-ray regime and paves the way for the development of novel X-ray optics such as high-resolution X-ray filters/monochromators, or X-ray quantum optics, to realize the phenomena such as Rabi splitting that are robust against disorders.

Pd/Y multilayer mirrors operating in the soft X-ray region are characterized by a high theoretical reflectance, reaching 65% at normal incidence in the 8-12 nm wavelength range. However, a severe intermixing of neighboring Pd and Y layers results in an almost total disappearance of the interfaces inside the multilayer structures fabricated by direct current magnetron sputtering and thus a dramatic reflectivity decrease. Based on grazing incidence X-ray reflectometry and X-ray photoelectron spectroscopy, we demonstrate that the stability of the interfaces in Pd/Y multilayer structures can be essentially improved by adding a small amount of nitrogen (4-8%) to the working gas (Ar). High resolution transmission electron microscopy shows that the interlayer width is only 0.9 nm and 0.6 nm for Y(N)-on-Pd(N) and Pd(N)-on-Y(N) interfaces, respectively. A well-defined crystalline texture of YN (200) is observed on the electron diffraction pattern. As a result, the measured reflectance of the Pd(N)/Y(N) multilayer achieves 30% at λ = 9.3 nm. The peak reflectivity value is limited by the remaining interlayers and the formation of the YN compound inside the yttrium layers, resulting in an increased absorption.