P. Wu

Growth and characterization of zinc sulfide films by conversion of zinc oxide films with H2S

Abstract Zinc sulfide films were prepared by conversion of zinc oxide films in the presence of hydrogen sulfide. The films which contained both the hexagonal and cubic forms of zinc sulfide were shown to be uniform and gave a measured band gap of 3.65 eV.

Growth and Characterization of Gallium (III) Oxide Films

Abstract A simple spray pyrolysis technique has been applied to the formation of dense, homogeneous gallium(III) oxide thin films on both silicon and silica substrates. The high quality of these films has been established by transmission electron microscopy, x-ray diffraction, optical spectra, and current-voltage measurements.

Growth of zinc oxide films by a novel ultrasonic nebulization and pyrolysis method

Abstract Films of ZnO have been grown on various substrates by an ultrasonic nebulization and pyrolysis method. The resulting films were characterized by x-ray diffraction, optical and electrical measurements. They were found to be single-phase, homogeneous, and uniform in thicknes. These films are comparable in quality to films prepared by more elaborate methods. Zinc oxide films are useful in a number of semiconductor applications.

Redetermination of crystal structure of zinc thiogallate

Abstract Zinc thiogallate crystallizes in the tetragonal space group I 4 2m with a = 5.297(1), c = 10.363(1) A . In this space group zinc and gallium are disordered in the 4(d) sites. Most of the AGa2X4 compounds crystallize with the defect chalcopyrite, space group I 4 where the A and Ga ions are ordered and half of the A-sites are vacant. The result of this work indicates that disordering of Zn and Ga ions can occur and result in a structure with higher symmetry. All of these compounds transmit in the far infrared and are potential infrared window materials.

Growth and characterization of thin films of Y2O3, La2O3 and La2CuO4

Abstract Films of Y 2 O 3 , La 2 O 3 , and La 2 CuO 4 were prepared by an ultrasonic nebulization and pyrolysis method using acetylacetonates of the corresponding metals in alcohol solvents as source materials. Homogeneous, uniform films with good adherence have been obtained using this simple technique. As-deposited yttrium and lanthanum oxide films were poorly crystallized. After postannealing in oxygen at higher temperature, they crystallized into cubic and hexagonal phases, respectively. Transparent yttrium and lanthanum oxide films have high electric breakdown voltages. Single phase polycrystalline La 2 CuO 4 thin films were obtained from a source solution with a La:Cu ratio of 2:1.

Growth and characterization of nickel-doped ZnS single crystals

Abstract Crystals of zinc sulfide containing up to 3 atomic percent of nickel were grown by chemical vapor transport using iodine as the transport agent. It was found that these crystals had the same long-wavelength IR transmission characteristics as pure ZnS. Furthermore, the addition of small amounts of nickel significantly increased the hardness of ZnS. These materials may be useful for the development of IR windows in the 8–12 μm range.

Growth and characterization of zirconium oxide films

Abstract Zirconium oxide films were deposited on silicon substrates by nebulizing alcohol solutions of zirconium acetylacetonate followed by pyrolysis and annealing of the oxide film in flowing oxygen for 30 minutes. The homogeneous uniform films obtained showed comparable properties to those reported from more elaborate procedures. The simplicity of this technique of ultrasonic nebulization and pyrolysis is of interest because of the commercial desirability of zirconium oxide films.

Preparation and Characterization of Members of the Chromium-Zirconium Oxide System.

Abstract : Samples of zirconium oxide containing 5-20 atomic percent chromium were prepared by double decomposition of the nitrates. X-ray diffraction analysis showed the products to be single phase. Magnetic suspectibility measurements were used to characterize the formal oxidation state of the chromium.

Preparation and characterization of members of the systems Cu(II)MgO and Cu(II)ZrO2

Abstract Cu(II) is known to prefer square planar or tetrahedral coordination in many oxides. The introduction of Cu(II) in the rock salt or fluorite structures would represent unusual structural behavior and be of interest in catalysis where new oxide supports are being investigated. The systems CuO/MgO and CuO ZrO 2 were studied and the nature of the products were characterized by X-ray diffraction analysis, temperature programmed reduction studies and magnetic susceptibility. Although some stabilization occurs for Cu(II) in ZrO2, a much greater stabilization was observed in the rock salt structure CuxMg1−xO.

Growth and characterization of zinc and cadmium thiogallate

In an attempt to prepare infrared materials which have properties superior to those of the II-VI chalcogenides, members of the system Zn1−xCdxGa2S4 (1≧x≧0) were prepared and their infrared transmission, hardness and thermal stability were measured. Whereas both ZnGa2S4 and CdGa2S4 transmitted in the infrared and have reasonable measured values for thermal stability and hardness, there is little improvement achieved by solid solutions.