The growth and characterization of Ge-C alloy thin films and solid phase equilibria for metal-silicon-oxygen ternary systems: Mg, Ca, Sr, Ba, Sc, Y, La, Ti, Zr and Hf

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5578617

Yuan, H

Thin films of pure germanium-carbon alloys (Ge[sub x]C[sub 1[minus]x] with 0 [le] x [le] 1) have been grown on Si and Al[sub 2]O[sub 3] substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray 0-20 diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00 eV to 0.85 eV for x = 0.0 to 1.0. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples have a bonding structure that is a mixture of sp[sup 2] and sp[sup 3] hybridizations. The solidus portion of the ternary phase diagrams of the type M-Si-O, where M=Mg, Ca, Sr, Ba, Sc, Y, La, Ti, Zr and Hf have been derived at 298K and 1 atm oxygen partial pressure by investigating the bulk reactions possible in these systems. A research effort has been made on the investigation of the growth of diamond thin films from a carbon containing solid-CI[sub 4], using laser ablation technique. The film grown by laser ablation from CI[sub 4] is mainly composed of carbon with small amounts of oxygen and iodine, indicated by x-ray photoelectron spectroscopy data. The Auger electron spectroscopy result shows the film grown contains a mixture of sp[sup 2] and sp[sup 3] hybridized carbon. Using x-ray powder diffraction and magnetic susceptibility measurement methods, the chemical stability of candidate interlayer materials between YBa[sub 2]Cu[sub 3]O[sub 7]-[sigma] and Si was studied. The results show that CaF[sub 2] reacts with YBCO while BaF[sub 2] is chemically stable with YBCO. LaGaO[sub 3] and Ca[sub 2]SiO[sub 4] are chemically stable with Si.

• Research Organization: California Univ., Los Angeles, CA (United States)
• OSTI ID: 5578617
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON COMPOUNDS
FABRICATION
STRUCTURAL CHEMICAL ANALYSIS
GERMANIUM ALLOYS
SEMICONDUCTOR MATERIALS
ABLATION
DIAMONDS
LASER RADIATION
PHASE DIAGRAMS
THIN FILMS
ALLOYS
CARBON
DIAGRAMS
ELECTROMAGNETIC RADIATION
ELEMENTAL MINERALS
ELEMENTS
FILMS
MATERIALS
MINERALS
NONMETALS
RADIATIONS
360601* - Other Materials- Preparation & Manufacture
360602 - Other Materials- Structure & Phase Studies