ABSTRACT
This Letter reports on investigations of novel, to the best of our knowledge, NiV(Ni93V7)/Ti multilayer mirrors for the operation in the wavelength region of 350-450â eV. Such mirrors are promising optical components for the Z-pinch plasma diagnostic. The NiV/Ti multilayers show superior structural and optical performance compared to conventional Ni/Ti multilayers. Replacing Ni with NiV in multilayers decreases interface widths and enhances the contrast of the refractive index between the absorber and spacer layers. The improvement of interface quality contributes to the enhancement in reflectance. Under the grazing incidence of 13°, a peak reflectivity of 25.1% at 429â eV is achieved for NiV/Ti multilayers, while 17.7% at 427â eV for Ni/Ti.
ABSTRACT
FeCo/Si is a promising material combination for polarized neutron supermirrors because of its appropriate optical constants. Five FeCo/Si multilayers with monotonically increasing FeCo layer thicknesses were fabricated. Grazing incidence x-ray reflectometry and high-resolution transmission electron microscopy were performed to characterize the interdiffusion and asymmetry of the interfaces. Selected area electron diffraction was used to determine the crystalline states of FeCo layers. It was found that the asymmetric interface diffusion layers existed in FeCo/Si multilayers. Furthermore, the FeCo layer started the transition from amorphous to crystalline when the thickness of the FeCo layer reached 4.0 nm.
ABSTRACT
Magnetized soft ferromagnetic films with micrometer thickness were studied. A FeSi film, with a total thickness of 2000 nm, separated by 10 nm-thick Ta interlayers, was fabricated using the direct-current magnetron sputtering technique. The thickness of each FeSi layer between adjacent Ta layers was 100 nm. Hysteresis loop measurement was used to characterize the magnetic properties of the layer. X-ray diffraction patterns and high-resolution transmission electron microscopy were used to characterize its texture. The experimental results showed that the FeSi film separated by Ta interlayers exhibited a lower saturation magnetization and a higher coercivity than those of the 1140 nm-thick FeSi film. The insertion of Ta interlayers resulted in the disappearance of the crystal plane of FeSi (221), and better texture of the crystal plane of FeSi (210). The FeSi film exhibited a crystal plane of FeSi (210) with a bcc crystalline structure. The Ta interlayers were partially amorphous, exhibiting crystal plane of Ta (002) and TaSi2 (310). The matching of magnetic properties between interlayers and soft magnetic layers played an important role in maintaining its soft magnetic properties.
ABSTRACT
Tintinnid ciliates are traditionally identified by their loricae; however, increasing evidence indicates that some lorica features (e.g. its length, spiraled structures) are not reliable. The vast majority of tintinnids inhabit the marine pelagial; merely, about thirty species live in freshwater. In the present study, two morphotypes with similar lorica shapes and opening diameters but deviating lorica lengths were isolated from freshwater samples collected at different water temperatures near Chongming Island in the Yangtze Estuary, China. The specimens were studied in vivo and after protargol staining, and their phylogenetic placement was inferred from three ribosomal RNA markers; further, cell division was investigated in the short morphotype. Based on the original descriptions, the longer morphotype is identified as Tintinnopsis longa nom. corr. Chiang, 1956, and the shorter one as Tintinnopsis tubuformis Chiang, 1956. Despite distinct differences in the lorica lengths, the identity of the three molecular markers in both morphotypes suggests conspecificity, which is supported by overlapping ranges in the lorica opening diameters and the length-independent features of the somatic ciliary pattern (e.g. number of kineties). Hence, we synonymized T. longa nom. corr. with T. tubuformis and neotypified the later species.
