Vapor Deposition of Lithium Tantalate with Volatile Double Alkoxide Precursors

1993 ◽  
Vol 335 ◽  
Author(s):  
Kueir-Weei Chour ◽  
Guangde Wang ◽  
Ren Xu
Keyword(s):  
Vapor Phase ◽  
Vapor Deposition ◽  
Single Phase ◽  
Thermal Evaporation ◽  
Variable Temperature ◽  
Substrate Surface ◽  
Partial Hydrolysis ◽  
High Deposition Rate ◽  
Deposited Films ◽  
Alkoxide Precursors

AbstractStoichiometric vapor deposition of LiTaO3 is demonstrated by thermal evaporation of volatile LiTa(OButn)6, controlled vapor phase partial-hydrolysis, and subsequent polycondensation reactions on a heated substrate surface. Fully dense, amorphous LiTaO3 film of up to 34 μm thick can be obtained at high deposition rate of 23 μm per hour. Single phase LiTaO3 films are obtained by annealing as deposited films. The vapor phase species responsible for the stoichiometric vapor deposition appeared to be Li2Ta2(OButn)12 from variable temperature mass spectrometry results.

Chemical Vapor Deposition of Sr1−xBaxNb2O6 Thin Films Using Metal Alkoxide Precursors

2000 ◽  
Vol 15 (8) ◽  
pp. 1702-1708
Author(s):  
Ruichao Zhang ◽  
Ren Xu
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Single Phase ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Thin Layers ◽  
Metal Alkoxide ◽  
Stoichiometry Control ◽  
Alkoxide Precursors

A novel two-step metalorganic chemical vapor deposition process was used in this study to prepare Sr1−xBaxNb2O6 (SBN) thin films. Two thin layers of single-phase SrNb2O6 and BaNb2O6 were deposited alternately on a silicon substrate, and the solid solution of SBN was obtained by high-temperature annealing. The stoichiometry control of the SrNb2O6 and the BaNb2O6 thin films was achieved through deposition process control, according to the evaporation characteristics of double metal alkoxide. The evaporation behavior of double metal alkoxide precursors SrNb2(1-OC4H9)12 and BaNb2(1-OC4H9)12 was studied, and the results were compared with the evaporation of single alkoxide Nb(1-OC4H9)5.

Autostoichiometric Vapor Deposition of Multicomponent Oxides

1994 ◽  
Vol 361 ◽  
Author(s):  
K.W. Chour ◽  
R. Xu
Keyword(s):  
Oxide Film ◽  
Vapor Phase ◽  
Vapor Deposition ◽  
Theoretical Basis ◽  
Substrate Surface ◽  
Reaction Scheme ◽  
Deposition Method ◽  
Precursor Molecule ◽  
Multicomponent Oxide ◽  
Molecular Precursor

ABSTRACTThe theoretical basis of an autostoichiometric vapor deposition method is discussed. We try to define and analyze through the stagnant film model for vapor deposition, the mechanism through which the stoichiometry of a multicomponent oxide film can be precisely controlled. It is found that the utilization of a thermally stable, heterometallic molecular precursor, and a chemical reaction scheme which partially protects the integrity of the precursor molecule during deposition are essential for autostoichiometric vapor deposition. An ideal deposition reaction is the vapor phase hydrolysis, substrate surface polycondensation of volatile double alkoxides. A simple low pressure apparatus can be used to realize autostoichiometric vapor deposition.

Laser CVD Process for High Speed Deposition of YSZ Films

2005 ◽  
Vol 475-479 ◽  
pp. 1213-1218 ◽  
Author(s):  
Takashi Goto
Keyword(s):  
Deposition Rate ◽  
Vapor Deposition ◽  
Gas Turbines ◽  
Physical Vapor Deposition ◽  
High Speed ◽  
Substrate Surface ◽  
Atmospheric Plasma ◽  
High Deposition Rate ◽  
Practical Applications ◽  
Laser Cvd

Thick oxide coatings have wide ranged applications such as oxidation protection, abrasives and thermal barrier coating (TBC). Yttria stabilized zirconia (YSZ) has been used for TBC in gas turbines. Generally, atmospheric plasma spray (APS) and electron-beam physical vapor deposition (EB-PVD) have been utilized in practical applications. Although chemical vapor deposition (CVD) provides high quality coatings, the deposition rate of CVD could have been too small for TBCs. We have recently developed a new laser CVD process achieving an extremely high deposition rate up to 660 ım/h for YSZ coatings on Al2O3 substrates and Ni-based super alloy substrates using Zr(dpm)4 and Y(dpm)3 precursors. An Nd:YAG laser with a high power of 250 W was introduced in a CVD chamber as a defocused beam in a diameter of 20mm covering a whole substrate surface. The YSZ coatings had a well-grown columnar structure with significant (200) orientation. Other oxides such as Y2O3, Al2O3 and TiO2 films were also prepared by laser CVD at high deposition rates around 1 mm/h.

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

scholarly journals Impedance Spectroscopic Study of Nickel Sulfide Nanostructures Deposited by Aerosol Assisted Chemical Vapor Deposition Technique

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1105
Author(s):  
Sadia Iram ◽  
Azhar Mahmood ◽  
Muhammad Fahad Ehsan ◽  
Asad Mumtaz ◽  
Manzar Sohail ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Nickel Sulfide ◽  
Variable Temperature ◽  
Complex Impedance ◽  
Equivalent Circuit Model ◽  
Chemical Vapor ◽  
Relaxation Processes ◽  
Impedance Plot ◽  
Vapor Deposition Technique

This research aims to synthesize the Bis(di-isobutyldithiophosphinato) nickel (II) complex [Ni(iBu2PS2)] to be employed as a substrate for the deposition of nickel sulfide nanostructures, and to investigate its dielectric and impedance characteristics for applications in the electronic industry. Various analytical tools including elemental analysis, mass spectrometry, IR, and TGA were also used to further confirm the successful synthesis of the precursor. NiS nanostructures were grown on the glass substrates by employing an aerosol assisted chemical vapor deposition (AACVD) technique via successful decomposition of the synthesized complex under variable temperature conditions. XRD, SEM, TEM, and EDX methods were well applied to examine resultant nanostructures. Dielectric studies of NiS were carried out at room temperature within the 100 Hz to 5 MHz frequency range. Maxwell-Wagner model gave a complete explanation of the variation of dielectric properties along with frequency. The reason behind high dielectric constant values at low frequency was further endorsed by Koops phenomenological model. The efficient translational hopping and futile reorientation vibration caused the overdue exceptional drift of ac conductivity (σac) along with the rise in frequency. Two relaxation processes caused by grains and grain boundaries were identified from the fitting of a complex impedance plot with an equivalent circuit model (Rg Cg) (Rgb Qgb Cgb). Asymmetry and depression in the semicircle having center present lower than the impedance real axis gave solid justification of dielectric behavior that is non-Debye in nature.

Colossal Magnetoresistance in Thick La0.7Ca0.3MnO3 Films

1995 ◽  
Vol 384 ◽  
Author(s):  
Randolph E. Treece ◽  
P. Dorsey ◽  
M. Rubinstein ◽  
J. M. Byers ◽  
J. S. Horwitz ◽  
...  
Keyword(s):  
Colossal Magnetoresistance ◽  
Single Phase ◽  
Laser Deposition ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Mr Effect ◽  
Deposited Films ◽  
Post Deposition

ABSTRACTThick films (0.6 and 2.0 μm) of the colossal magnetoresistance (CMR) material, La0.7Ca0.3MnO3 (LCMO), have been grown by pulsed laser deposition (PLD). The films were grown from single-phase LCMO targets in 100 mTorr 02 pressures and the material deposited on (100) LaAlO3 substrates at deposition temperatures of 800°C. The deposited films were characterized by X-ray diffraction (XRD), magnetic field-dependent resistivity, and Rutherford backscattering spectroscopy (RBS). The LCMO films were shown by XRD to adopt an orthorhombic structure. Brief post-deposition annealing led to ~50,000% and ~12,000% MR effect in the 0.6 μm and 2.0 μm films, respectively.

N-rich GaNAs with High As Content Grown by Metalorganic Vapor Phase Epitaxy

2003 ◽  
Vol 798 ◽  
Author(s):  
Akitaka Kimura ◽  
H. F. Tang ◽  
C. A. Paulson ◽  
T. F. Kuech
Keyword(s):  
Vapor Phase ◽  
Single Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Band Gap Energy ◽  
Vapor Phase Epitaxy ◽  
Miscibility Gap ◽  
X Ray Diffraction ◽  
Specular Surfaces ◽  
Rich Side ◽  
Absorption Measurements

ABSTRACTGaN1-yAsy epitaxial alloys on the N-rich side with high As content were grown by metalorganic vapor phase epitaxy. They had specular surfaces and the single-phase epitaxial nature was confirmed by X-ray diffraction. The As incorporation increased through both a decrease in the growth temperature and V/III ratio. These trends were similar to that found in other III-V alloy systems which exhibit a large miscibility gap and the anion incorporation was considered to have been limited kinetically under the conditions of the low V/III ratio. The range of achieved As content was extended up to y=0.067, which is a composition well within the miscibility gap. The As-content dependence of the band gap energy was determined by optical absorption measurements and large bowing parameter of 16.8 ± 0.9 eV was determined.

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