Amorphous chalcogenide AgSbS2 films prepared by pulsed laser deposition

The pulsed laser deposition technique has been applied to prepare amorphous ternary AgSbS films. The films were prepared from AgSbS₂ bulk glass using a KrF excimer laser. The composition of prepared films according to the results of the energy dispersive X-ray analysis and the Rutherford backscattering was close to bulk one. Optical transmission and spectral dependence of the refractive index proved the good optical quality of the films. The Ar⁺ ion laser dot exposures of the films show a potential applicability of the films as a new type of optical recording material. PACS 78.66.Jg; 81.15.Fg; 81.40.Wx     

Glasses for lithography

The highest resolution in a lithographic process is often determined by the properties of the resist material. With the currently used polymeric resists, a resolution of better than 100 nm has been achieved under manufacturing conditions, but the future nanoscale devices will require a 10 times superior resolution. In this paper we present an overview of the resist materials, especially with regard to limiting resolution. In principle, inorganic resists should have higher limiting resolution than polymer resists due to smaller fundamental structural units and stronger bonds in the former. However, compositional and/or structural inhomogeneities may limit their ultimate resolution. New results are presented that indicate chalcogenide glasses as promising photo and electron beam resists, which also have the advantages of greater hardness, resistance to acids, easy fabrication in thin film form, and the unique phenomena like radiation enhanced diffusion.     

Five-step phase-shifting algorithms with unknown values of phase shift

The presented work offers new algorithms for phase evaluation in interferometric measurements. Several phase-shifting algorithms with an arbitrary but constant phase-shift between captured intensity frames are proposed. These phase calculation algorithms need to measure five frames of the intensity of the interference field. The algorithms are similarly derived as so called Carré algorithm. The phase evaluation process then does not depend on the linear phase shift errors. Furthermore, the detailed analysis of the algorithms with respect to most important factors, which affect interferometric measurements, is carried out. It is also studied the dependency of the evaluation algorithms on the phase shift values, and the proposed phase calculation algorithms are compared with respect to the resulting phase errors. The influence of most important factors in the measurement and evaluation process was simulated as systematic and random errors using a proposed mathematical model.     

Bonding Properties of a Novel Inorganometallic Complex, Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) (iPr-DAB = N,N'-Diisopropyl-1,4-diaza-1,3-butadiene), and its Stable Radical-Anion, Studied by UV-Vis, IR, and EPR Spectroscopy, (Spectro-) Electrochemistry, and Density Functional Calculations

Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) was synthesized and characterized by UV-vis, IR, (1)H NMR, (13)C NMR, (119)Sn NMR, and mass (FAB(+)) spectroscopies and by single-crystal X-ray diffraction, which proved the presence of a nearly linear Sn-Ru-Sn unit. Crystals of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB).3.5C(6)H(6) form in the triclinic space group P&onemacr; in a unit cell of dimensions a = 11.662(6) ?, b = 13.902(3) ?, c = 19.643(2) ?, alpha = 71.24(2) degrees, beta = 86.91(4) degrees, gamma = 77.89(3) degrees, and V = 2946(3) ?(3). One-electron reduction of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) produces the stable radical-anion [Ru(SnPh(3))(2)(CO)(2)(iPr-DAB)](*-) that was characterized by IR, and UV-vis spectroelectrochemistry. Its EPR spectrum shows a signal at g = 1.9960 with well resolved Sn, Ru, and iPr-DAB (H, N) hyperfine couplings. DFT-MO calculations on the model compound Ru(SnH(3))(2)(CO)(2)(H-DAB) reveal that the HOMO is mainly of sigma(Sn-Ru-Sn) character mixed strongly with the lowest pi orbital of the H-DAB ligand. The LUMO (SOMO in the reduced complex) should be viewed as predominantly pi(H-DAB) with an admixture of the sigma(Sn-Ru-Sn) orbital. Accordingly, the lowest-energy absorption band of the neutral species will mainly belong to the sigma(Sn-Ru-Sn)-->pi(iPr-DAB) charge transfer transition. The intrinsic strength of the Ru-Sn bond and the delocalized character of the three-center four-electron Sn-Ru-Sn sigma-bond account for the inherent stability of the radical anion.     

Determination of uranium by thermal and epithermal neutron activation in natural waters and in human urine

Uranium is determined via its ²³⁹U nuclide (74.0 keV, t_{$\text{1}\text{2}$} = 23.5 min) in natural waters down to 0.03 ng U ml^-1 after preconcentration with activated carbon and oxine; 30-min irradiation and counting times are used. No preconcentration is required for samples containing more than 4 ng U ml^-1 with 10-min irradiation and counting times. Uranium in urine can be determined under a boron shield at the 5 ng ml^-1 level after 30-min irradiation and counting.     

Thermodynamic Properties and Melting Behavior of Bi–Sn–Zn Alloys

Summary. The partial and integral enthalpies of mixing of liquid Bi–Sn–Zn alloys were determined at 500°C by a drop calorimetric technique using a Calvet-type microcalorimeter. The ternary interaction parameters in the Bi–Sn–Zn system were fitted using the Redlich-Kister-Muggianu model for substitutional solutions, and isoenthalpy curves of the integral molar enthalpy of mixing at 500°C were constructed. Furthermore, a DSC technique was used to determine the liquidus temperatures in three sections (3, 5, and 7 at.% Zn) as well as the invariant reaction temperature of the ternary eutectic L ⇄ (Bi) + (Sn) + (Zn). The ternary eutectic reaction was found at 135°C.     

Theoretical studies of photodissociation and rydbergization in the first triplet state (3s3A″2) of ammonia

Ab initio investigations at the RHF and CI levels have been carried out on a section of the potential energy surface of the Rydberg 3s³A″₂ state of NH₃ leading to dissociation into NH₂(²B₁) and H(²S). It was found that the barrier towards dissociation is due to a Rydberg-valence transformation. The barrier height calculated with the CI wavefunction is significantly smaller than at the RHF level The results may explain the difficulties associated with experimental observation of the 3s³A″₂ state.     

Renormalized inner projection—a case study: The octic oscillator

The upper and lower bounds of a harmonic oscillator with an octic perturbation are studied with the use of renormalized inner projection. It is shown that this relatively simple technique works even in the infinite coupling constant limit. Symbolic computation is very convenient and useful in these types of problems, where only a finite number of operations are required.     

Synthesis and x-ray crystal structure of [(THF)Zn(O(2)(OH)SiR)](4) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))): enroute to larger aggregates

Reaction of aminosilanetriol RSi(OH)(3) (1) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) with diethyl zinc at room temperature in 1:1 stoichiometric ratio affords [(THF)Zn(O(2)(OH)SiR)](4) (2) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) in good yield. The single-crystal X-ray diffraction studies reveal that 2 is monoclinic, P2(1), with a = 17.117(3) A, b = 16.692(5) A, c = 17.399(4) A, alpha = gamma = 90 degrees, beta = 91.45(7) degrees, and Z = 2. The molecular structure of 2 contains two puckered eight-membered Zn(2)Si(2)O(4) rings, which are connected by the Zn-O bonds and form two planar four-membered Zn(2)O(2) rings. Compound 2 contains an unreacted hydroxyl group on each silicon atom, and hence, we carried out the reactions of 2 with dimethylzinc and methyllithium to form [Zn(4)(THF)(4)(MeZn)(4)(O(3)SiR)(4)] (3) (R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))) and [(L)ZnLi(O(3)SiR)](4) (4) (L = 1,4-(Me(2)N)(2)C(6)H(4), R = (2,6-i-Pr(2)C(6)H(3))N(SiMe(3))), respectively. This suggested that 2 could be an intermediate product formed during the synthesis of 3 and 4.