Characterization of molecular nitrogen in III-V compound semiconductors by near-edge x-ray absorption fine structure and photoemission spectroscopies

Formation of molecular nitrogen under low-energy nitrogen bombardment of III-V compound semiconductor surfaces has been studied by photoemissionspectroscopy around N 1s core-level and near-edge x-ray absorption fine structure(NEXAFS) around NK edge. Interstitial molecular nitrogen N₂ has been formed in all of the samples under consideration. The presence of N₂ produces a sharp resonance in low-resolution NEXAFSspectra, showing the characteristic vibrational fine structure in high-resolution measurements, and at the same time, a new peak, shifted toward higher binding energies for several eV, in all N 1sphotoemissionspectra.This work was supported by the Australian Synchrotron Research Program, which is funded by the Commonwealth of Australia under the Major National Research Facilities Program, and the Research Grant from the Ministry for Science, Education and Sport of the Republic of Croatia

Comparative Structural and Optical Properties of Different Ceria Nanoparticles

Herein a comparative study of five nanocrystalline cerium oxides (CeO2-delta) synthesised by different methods and calcined at 500 degrees C is reported. XRPD analysis showed that stoichiometry parameter delta, crystallite size/strain and lattice constant were only slightly affected by the method utilized. All ceria nanoparticles are nearly spherical in shape with faceted morphology, free of defects and with a relatively uniform size distribution. The average microstrain was found to be approximately 10 times higher than that of bulk counterpart. The absorption edge of nanocrystalline materials was shifted towards a higher wavelengths (red shift) in comparison with bulk counterpart, and band gap values were in the range 2.7-3.24 eV (3.33 eV for bulk counterpart)

Digital transformation of business-to-government reporting:An institutional work perspective

Traditional business-to-government reporting is a core remit of the accounting function but is associated with a significant administrative burden on business. This burden is a major obstacle hindering business efforts to achieve core efficiency and innovation objectives. We use the conceptual lens of institutional work to examine how traditional business-to-government reporting is abolished and how digital reporting is established to replace it in attempts to reduce administrative burden but without compromising regulation effectiveness. We adopt a comparative approach to analyse qualitative evidence from three jurisdictions, namely, Netherlands, United Kingdom, and Australia. Regulators across these jurisdictions have been both pioneers and leaders internationally to transform business-to-government reporting in multi-agency settings. Our analyses illustrate how institutional work to develop digital business-to-government reporting across the jurisdictions was shaped by international influences and local factors. We also illuminate how actor engagement issues and the intertwined and mutually reinforcing nature of a mosaic of forms of institutional work shaped the path of these transformations. The study contributes to existing research by explaining how supportive conditions and structures are brought about and made to coalesce in the regulatory business reporting space for digital reporting to become established and widely adopted by business

Characterisation of molecular nitrogen in ion-bombarded compound semiconductors by synchrotron-based absorption and emission spectroscopies

We have studied formation of molecular nitrogen under low-energy nitrogen bombardment in a range of compound semiconductors by synchrotron-based X-ray photoelectron spectroscopy (XPS) around N 1s core-level and near-edge X-ray absorption fine structure (NEXAFS) around N K-edge. We have found interstitial molecular nitrogen, N(2), in all samples under consideration. The presence of N(2) produces a sharp resonance in low-resolution NEXAFS spectra at around 400.8 eV, showing the characteristic vibrational fine structure in high-resolution measurements. At the same time, a new peak, shifted towards higher binding energies, emerges in all N 1s photoemission spectra. We have found a shift of 7.6 eV for In-based compounds and 6.7 eV for Ga-based compounds. Our results demonstrate that NEXAFS and core-level XPS are complementary techniques that form a powerful combination for studying molecular nitrogen in compound semiconductors, such as GaSb, InSb, GaAs, InN, GaN or ZnO. (C) 2009 Elsevier Ltd. All rights reserved.

Optimization of photoluminescence of Y2O3:Eu and Gd2O3:Eu phosphors synthesized by thermolysis of 2,4-pentanedione complexes

Spherical shaped nanoparticles of series Y2-xEuxO3 (x = 0.06, 0.10, 0.20, and 2) and Gd2-xEuxO3 (x = 0.06, 0.10) were prepared by thermolysis of 2,4-pentanedione complexes of Y, Gd, and Eu. The bixbyite phase of Gd2-xEuxO3 samples was formed at 500 degrees C, whereas the thermal decomposition of Y and Eu complexes' mixtures occurred at higher temperatures. Linearity in the concentration dependence on lattice parameter confirmed the formation of solid solutions. The distribution of Eu3+ in Gd2-xEuxO3 was changed with thermal annealing: in the as-prepared sample (x = 0.10) the distribution was preferential at C-3i sites while in the annealed samples, Eu3+ were distributed at both C-2 and C-3i sites. Rietveld refinement of site occupancies as well as emission spectra showed a random distribution of cations in Y2-xEuxO3. The photoluminescence (PL) measurements of the sample showed red emission with the main peak at 614 nm (D-5(0)-F-7(2)). The PL intensity increased with increasing concentration of Eu3+ in both series. Infrared excitation was required to obtain good Raman spectra. The linear dependence of the main Raman peak wavenumber offers a non-destructive method for monitoring the substitution level and its homogeneity at the micron scale