In this paper we investigate FePd thin alloy film with a copper admixture composed of nanometer-sized grains. [Fe(0.9 nm)/Pd(1.1 nm)/Cu(d nm)] x 5 multilayers were prepared by thermal deposition at room temperature in UHV selleck chemical conditions on Si(100) substrates covered by 100 nm SiO2. The thickness of the copper layer has been changed from 0 to 0.4 nm. After deposition, the multilayers were rapidly annealed at 600 degrees C in a nitrogen atmosphere,
which resulted in the creation of the FePd:Cu alloy. The structure of alloy films obtained this way was determined by x-ray diffraction (XRD), glancing angle x-ray diffraction, and x-ray absorption fine structure (EXAFS). The measurements clearly showed that the L1(0) FePd:Cu nanocrystalline phase has been formed during the annealing process for all investigated copper compositions. This paper concentrates on the crystallographic grain features of FePd:Cu alloys and illustrates that the EXAFS technique, supported by XRD measurements, can help to extend the information about grain size and grain shape of poorly crystallized materials. We show that, using an appropriate learn more model of the FePd:Cu grains, the comparison of EXAFS and XRD results gives a reasonable agreement. (c) 2011
American Institute of Physics. [doi:10.1063/1.3553856]“
“PURPOSE: To compare the central corneal thickness (CCT) in normal eyes, eyes with keratoconus, and eyes after laser in situ keratomileusis (LASIK) using 3 methods.
SETTING: Cornea Clinic, Grewal Eye Institute, Chandigarh, India.
METHODS: In this study, CCT was measured by sequential
Scheimpflug imaging, spectral-domain anterior segment optical www.selleckchem.com/products/VX-809.html coherence tomography (AS-OCT), and ultrasound (US) pachymetry.
RESULTS: Each of the 3 groups comprised 50 eyes. There were no differences between the 3 groups in age, sex, or intraocular pressure. In normal eyes, CCT was statistically significantly higher by US pachymetry (mean 525.8 mu m +/- 41.4) [SD] than by Scheimpflug imaging (mean 519.4 +/- 40.9 mu m) and AS-OCT (mean 517.9 +/- 41.5 mu m) (both P<.001). In keratoconus eyes, CCT by US pachymetry (mean 446.4 +/- 57.9 mu m) was statistically significantly higher than by Scheimpflug imaging (mean 439.6 +/- 62.1 mu m) (P = .002) and AS-OCT (mean 441.8 +/- 58.4 mu m) (P = .007). In post-LASIK eyes CCT by US pachymetry (mean 462.4 +/- 44.7 mu m) was significantly higher than by Scheimpflug imaging (mean 457.9 +/- 33.6 mu m) (P = .012) and AS-OCT (mean 455.4 +/- 43.2 mu m) (P<.001). In all groups, CCT measured by Scheimpflug imaging and AS-OCT was similar.
CONCLUSIONS: There was a statistically significant difference between Scheimpflug imaging and US pachymetry and AS-OCT, with US pachymetry measurements being consistently thicker. Thus, CCT should be interpreted in the context of the instrument used.