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The use of the high free-electron concentration in heavily doped semiconductor enables the realization of plasmons. We report a novel approach to generate plasmons in Ga:ZnO (GZO) thin films in the wide spectral range of ∼1.87–10.04 eV. In the grown GZO thin films, dual-ion beam sputtering (DIBS) instigated plasmon is observed because of the formation of different metallic nanoclusters are reported. Moreover, formation of the nanoclusters and generation of plasmons are verified by field emission scanning electron microscope, electron energy loss spectra obtained by ultraviolet photoelectron spectroscopy, and spectroscopic ellipsometry analysis. Moreover, the calculation of valence bulk, valence surface, and particle plasmon resonance energies are performed, and indexing of each plasmon peaks with corresponding plasmon energy peak of the different nanoclusters is carried out. Further, the use of DIBS-instigated plasmon-enhanced GZO can be a novel mean to improve the performance of photovoltaic, photodetector, and sensing devices.

The barium hexaferrite, BaFe12O19, microcrystals were obtained by the flux crystal growth method and were characterized by XRD, SEM, and TEM methods. XPS measurements were carried out on a powder sample. The binding energy differences between the O 1s and cation core levels, ΔBa= BE(O 1s) – BE(Ba 3d5/2) and ΔFe= BE(O 1s) – BE(Fe 2p3/2), were used to characterize the valence electron transfer on the formation of Ba–O and Fe–O bonds. The chemical bonding effects were considered on the basis of our XPS results measured for BaFe12O19and the earlier published structural and XPS data for other Ba- or Fe-containing oxide compounds. The band structure of BaFe12O19was calculated by spin-polarized DFT methods and compared to the valence band spectrum measured by the XPS method.

The La2O3/Si thin films have been deposited by reactive DC magnetron sputtering. Amorphous state of La2O3layer has been shown by RHEED observation. Top surface chemistry of the a-La2O3has been evaluated with layer-by-layer depth profiling by ion bombardment and XPS measurements. It was found by core level spectroscopy that the top surface of the a-La2O3film consists of hydrocarbon admixture, lanthanum carbonate, and hydroxides that formed as a result of contact with air atmosphere. Thickness of this top surface modified layer is below 1 nm for a contact time of ∼1.5 h with air at normal conditions.

The microcrystals of monoclinic europium molybdate, α-Eu2(MoO4)3, have been fabricated by solid-state synthesis at T= 753–1273 K for 300 h. The crystal structure of α-Eu2(MoO4)3has been refined by the Rietveld method and was found to belong to the space group C2/cwith unit cell parameters a= 7.5576(1), b= 11.4709(2), c= 11.5158(2) Å, and β = 109.278(1)° (RB= 3.39%). About 40 narrow Raman lines have been observed in the Raman spectrum of the α-Eu2(MoO4)3powder sample. The luminescence spectra of α-Eu2(MoO4)3under excitation at 355 and 457.9 nm reveal domination of induced electric dipole transition 5D0→ 7F2and the presence of ultranarrow lines at 5D0→ 7F0and 5D1→ 7F0transitions.

Nanocrystalline yttrium oxide (Y2O3) thin films were made by sputter deposition onto silicon (100) substrates keeping the deposition temperature fixed at 300 °C. The surface/interface chemistry, Y–O bonding, and optical constants of the Y2O3film surface and Y2O3–Si interface were evaluated by the combined use of X-ray photoelectron spectroscopy (XPS), depth-profiling, and spectroscopic ellipsometry (SE). XPS analyses indicate the binding energies (BEs) of the Y 3d doublet; i.e., the Y 3p5/2and Y 3d3/2peaks are located at 117.0 and 119.1 eV, respectively, characterizing yttrium in its highest chemical oxidation state (Y3+) in the grown films. The optical model is constructed based on the XPS depth profiles, which indicate that the Y2O3//Si heterostructure can be represented with Y2O3filmYxSiyOzinterfacial compoundSi substrate. Such a model accounts for the experimentally determined ellipsometry functions and accurately produces the dispersive index of refraction (n(λ)) of Y2O3and YxSiyOz. The n(λ) of Y2O3and YxSiyOzfollows Cauchy’s dispersion relation, while the YxSiyOzformation accounts for degradation of optical quality.

Polycrystalline α-GeO2, space group P3221, has been prepared by low-temperature chemical synthesis. α-GeO2electronic structure has been evaluated comparatively by X-ray photoelectron spectroscopy (XPS) and ab initio calculations. The oxygen vacancies have been formed in α-GeO2by Ar+ion bombardment at ion energy 2.4 keV. The appearance of oxygen-vacancy-induced new states in the band gap has been detected by XPS and theoretical analysis. It has been shown that oxygen monovacancy generation provides defect states in the valence band, in the band gap, and in the conduction band.

Abstract: Noncentrosymmetric crystals of iodates and titanates have been systematized, and the principles of the design of new nonlinear optical materials by means of revealing empirical composition-structure-property relationships have been considered. It is demonstrated that, in the diagram of chemical bond lengths, noncentrosymmetric crystals of simple and binary iodates and titanates are located within the rosette formed by three partially intersecting ellipses. The empirical dependences of the nonlinear optical susceptibility χ(2) of the crystal on the length of the shortest metal-oxygen chemical bond L are established for iodates and titanates. These dependences exhibit maxima at L = 177 and 180 pm for iodates and L = 177 and 188 pm for titanates.

A theoretical model was presented to deal with optical frequency conversion in mixed nonlinear crystals with a small random variation of the composition ratio. For the pump of collimated Gaussian beams, the output powers of sum and difference frequency generations were deduced upon the assumption that the randomness is subject to the stationary Gaussian stochastic process. The induced efficiency reduction relies on the variance and correlation scales of a given varying composition ratio, which widens the phase matching bandwidth as well. The result was generalized to combined mixed crystals involving the gradual index variation. Acceptable composition ratios in different cases were also developed, as they could be applied more easily in practice. The study also includes an analysis of an intentional sinusoidal compositional modulation, which provokes potential applications in the frequency conversions of multiband lasers. The model was also exemplified by applying it to AgGa_1−xIn_xSe_2.

The effect of 1.5 keV Arion irradiation on the (001) surfaces of potassium titanyl arsenate, KTiOAsO4(KTA), has been investigated using reflection high-energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS). The (001) KTA surface is very sensitive to 1.5 keV Arion irradiation which induces significant structural modification in the top surface layers. The bonds in the KTA crystal lattice are relatively less unstable when compared to ; reduction of As5ions with the formation of As0and partial As loss from the top surface occurs with Arion irradiation. The formation of an unstable layer with chemically active and passive arsenic states may be a factor reducing the optical parameters and durability of nonlinear devices involving KTA.

Structural and electronic properties of the as‐grown (011) crystal face and the mechanically polished (001) surface of potassium titanyl phosphate (KTiOPO4or KTP) have been investigated by core‐level x‐ray photoelectron spectroscopy and reflection high‐energy electron diffraction (RHEED). With XPS analysis the original element binding energies, Auger parameters for K 2p3/2and P 2p core levels, relative element contents and valence band structure have been determined for both crystal cuts. A great depletion of O, K and P in the (011) face with respect to the (001) surface was discovered on comparison of element peak areas. The Ti 2p3/2peak areas were virtually the same for both cuts investigated. The relative element contents at the (001) surface were very close to the formal composition of KTiOPO4, so it is optimal to use the polished (001) KTP surface cleaned by ion bombardment and the Ti 2p3/2core level as standards for determination of the chemical composition of doped crystal surfaces. Copyright © 2002 John Wiley & Sons, Ltd.

Structural and electronic properties of the as-grown (011) crystal face and the mechanically polished (001) surface of potassium titanyl phosphate (KTiOPO4 or KTP) have been investigated by core-level x-ray photoelectron spectroscopy and reflection high-energy electron diffraction (RHEED). With XPS analysis the original element binding energies, Auger parameters for K 2p3/2 and P 2p core levels, relative element contents and valence band structure have been determined for both crystal cuts. A great depletion of O, K and P in the (011) face with respect to the (001) surface was discovered on comparison of element peak areas. The Ti 2p3/2 peak areas were virtually the same for both cuts investigated. The relative element contents at the (001) surface were very close to the formal composition of KTiOPO4, so it is optimal to use the polished (001) KTP surface cleaned by ion bombardment and the Ti 2p3/2 core level as standards for determination of the chemical composition of doped crystal surfaces. Copyright © 2002 John Wiley & Sons, Ltd.

The liquidus surface structure and field of LiB3O5(LBO) primary crystallization have been revealed in Li2O‐B2O3‐MoO3ternary system. The optimization of charge composition and growth conditions results in large volume optical quality LBO single crystals yielding. Crystallographic properties and real defect structure of grown LBO single crystals have been investigated by X‐ray powder diffraction method and X‐ray reflection topography. The volume of the crystals is partly free of any structural imperfections.

Cell parameters a and c. Curie temperature and density of Ti-doped LiNbO3 crystals have been measured as functions of molar fraction of an admixture x. It has been found that a (x) and ρ (x) have a change of slopes in the locality of x0 ≃ 0,6 mol. %. The conclusion has been made that this anomaly is the result of variation of the solid solution chemical formula. A role of different physical mechanisms in a refractive indices increase above and below x0 has been estimated.

The phase correction of a vortex laser beam is undertaken in the closed-loop adaptive system including a Hartmann–Shack wavefront sensor with singular reconstruction technique and a bimorph piezoceramic mirror. After correction the vortex doughnutlike beam is focused into a beam with bright axial spot that considerably increases the Strehl ratio and optical system resolution. Since the phase break cannot be exactly reproduced on the flexible mirror surface, off-axis vortices appear in the far field at the beam periphery.

Reconstruction the phase front of a vortex laser beam is conducted by use of a Hartmann-Shack wavefront sensor. The vortex beam in the form of the Laguerre-Gaussian LG_0^1 mode is generated with the help of a spiral phase plate. The new reconstruction technique based on measured wavefront gradients allows one to restore the singular phase surface with good accuracy, whereas the conventional least-squares approach fails.

The title compounds (x = 0.25, 0.5, 0.75, 0.9) are prepared by solid state reaction of Al(NO3)3, H3BO3, K2CO3, and Rb2CO3(various heat treatments between 400 and 850 °C for 7—48 h).