CHEMILUMINESCENT REACTIONS OF SO

Abstract— The rapid bimolecular reaction SO + O₃= SO₂+O₂+ 106 kcal/mole
yields electronically excited SO₂ in the ³B ₁ and ¹B₂ states with some vibrational excitation, as well as SO₂ in its electronic ground state. It is shown that k₁ = 1.5 x 10¹² exp (-2100/ RT ) cm² mole^-1 s-¹ and that the formation of electronically excited SO₂ involves higher activation energies.     

Rotational and hyperfine parameters of NH2(X2B1) from LMR spectra

Seventeen rotational transitions up to N=7 of the NH₂ radical in its ground vibronic state have been measured by far infrared laser magnetic resonance spectroscopy. Analysis of the Zeeman patterns and hyperfine structure yields precise rotational, spin-rotational and distortion parameters, and isotropic and anisotropic hyperfine interaction parameters for both ¹⁴N and ¹H nuclei.     

Thermoelectric power of bismuth nanocomposites

Because of the increase in the electronic density of states in low-dimensional systems, semiconductor quantum wires constitute a most promising thermoelectric material. We report here the first experimental observation of a very large enhancement of the thermoelectric power of composites containing bismuth nanowires with diameters of 9 and 15 nm, embedded in porous alumina and porous silica. The temperature dependence of the electrical resistance shows that the samples are semiconductors with energy gaps between 0.17 and 0.4 eV, consistent with the theoretical predictions.     

Resistance,magnetoresistance, and thermopower of zinc nanowire composites

We report a very large enhancement of the thermopower of 4 nm diameter metallic Zn nanowires, with a temperature dependence that is consistent with that of their electrical resistivity and the Mott formula. The temperature dependence of the resistance, magnetoresistance, and thermopower of composites consisting of 15, 9, and 4 nm diameter Zn nanowires imbedded in porous host materials is reported. The 15 nm wires are metallic. The smaller wires show 1D weak localization, but the electrical resistivity mostly follows a T(-1/2) law, and the thermopower of the 4 nm wires saturates at -130 microV/K.     

Laser magnetic resonance spectrum of the PH2 radical

The PH₂ radical in its ground vibrational and electronic state has been detected by far infrared laser magnetic resonance absorption using the 118.6 μm line of the water vapour laser. The spectrum has been assigned to Zeeman components of the 5₃₂ – 6₄₃ rotational transition.     

Carbon monoxide and hydrogen adsorption on a calcium-covered polycrystalline platinum foil

The effect of Ca on the adsorption of CO and H₂ is investigated. Ca influences the desorption of both species.     

Highly uniform AlGaAs/GaAs and InGaAs(P)/InP structures grown in a multiwafer vertical rotating susceptor MOVPE reactor

Highly uniform AlGaAs/GaAs and InGaAs(P)/InP epitaxial layers have been grown in a vertical rotating susceptor MOVPE reactor capable of accommodating three 2′ wafers. The unique water-cooled “showerhead”-type injection distributor which is located 1.5 cm above the substrates ensures a uniform reactant distribution, resulting in uniform growth over a wide range of growth conditions. Periodic multilayer and single layer structures have been used to investigate the thickness and compositional uniformities. The thickness variations over a radial distance of 48 mm for three wafers grown in the same run are within ± 2% for both AlGaAs and InGaAs layers, resulting in a standard deviation of only 0.9%. The gallium concentration of an InGaAs layer varies from 46.88% to 47.01% over the same radial distance with the standard deviation of 0.043%. Measurements of InGaAsP layers grown onto 2′ InP wafers with different alloy compositions show good compositional uniformity yielding standard deviations within 4.4 nm in PL wavelength and 135 ppm in lattice mismatch over a 46 mm radial distance.