New metal-organic chemistry of barium, an aqueous synthesis for volatile alkaline earth complexes, and synthesis and characterization of Tl-Ba-Ca-Cu-O thin films by metal-organic chemical vapor deposition
The synthesis and characterization of six fluorine-free Barium MOCVD (metal-organic chemical vapor deposition) precursors based upon encapsulating [beta]-ketoiminate-polyether ligation and having the general formula Ba(RCOCHC (NR[prime])R[prime])2 (R[prime] = [sup t]butyl, R[prime] = polyether, and R[double prime] = methyl or [sup t]butyl) is reported. The complexes were prepared by a nonaqueous approach which employs BaH[sub 2] and the corresponding [beta]-ketoimine. These complexes have been characterized by [sup 1]H and [sup 13]C NMR spectroscopy, elemental analysis, mass spectroscopy, cryoscopic molecular weight determination, thermogravimetric analysis, and single crystal X-ray structural analysis. These complexes serve as volatile barium MOCVD precursors. BaPbO[sub 3] films have been grown using the barium [beta]-ketoiminate complexes and Pb(dipivaloylmethanate)[sub 2] as the barium and lead sources, and have been characterized. Investigation of thermolytic decomposition of the barium [beta]-ketoiminate complexes led to identification of 2-methyl-4-[sup 4]butylpyridine (17), pinacolone, and 2,2-dimethyl-5-imino-3-hexanone as the major organic thermolysis products of 11, 12, and 13. The MOVCD synthesis of Tl-Ba-Ca-Cu-O thin films on novel substrates has been investigated. These films were prepared in three steps: deposition of Ba-Ca-Cu-O-(F) thin films by MOCVD; defluorination via water/oxygen anneal; thallination using volatile thallium oxides. Films were characterized by X-ray diffraction, variable temperature magnetization, variable temperature conductivity, and scanning and transmission electron microscopy. Attempts at preparing Tl-Ba-Ca-Cu-O thin films on Pt resulted in formation of a non-contiguous Ba-Ca-Cu-O film. Tl[sub 2]Ba[sub 2]Ca[sub 1]Cu[sub 2]O[sub x] on Au/YSZ, Au, and LaAlO[sub 3] show preferential orientation of crystallite c-axes. Au-Cu alloy formation was confirmed by TEM/EDS for Tl[sub 2]Ba[sub 2]Ca[sub 1]Cu[sub 2]O[sub x] thin films on Au.
- Research Organization:
- Northwestern Univ., Chicago, IL (United States)
- OSTI ID:
- 7072311
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKALINE EARTH METAL COMPLEXES
CHEMICAL VAPOR DEPOSITION
BARIUM OXIDES
PRECURSOR
CALCIUM OXIDES
CUPRATES
INTERMETALLIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
THALLIUM OXIDES
THIN FILMS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
COMPLEXES
COPPER COMPOUNDS
DEPOSITION
FILMS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SURFACE COATING
THALLIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
400201 - Chemical & Physicochemical Properties