Modified Pechini Synthesis of Oxide Powders and Thin Films

AbstractContrary to the commonly accepted model, we conclude that the zinc interstitials in Zn1+xO are not ionized. Instead, the electron pair associated with the interstitial zinc is trapped in a metal—metal bond. The increase in conductivity on initial reduction of zinc oxide is associated with impurities such as silicon which are compensated by extra oxygen unless removed by reduction. Zinc oxide powders and thin films were prepared with the dopants B, Al, Ga, In, and Ge. By using high temperatures and highly reducing conditions, conductivities 1000 times higher than previously reported for powders were obtained for some of our powders.

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Synthesis and characterization of sol-gel derived lanthanum hexaluminate powders and films

Journal of Materials Research ◽

10.1557/jmr.1995.0071 ◽

1995 ◽

Vol 10 (1) ◽

pp. 71-76 ◽

Cited By ~ 34

Author(s):

Michael K. Cinibulk

Keyword(s):

Thin Films ◽

Solid State ◽

Sol Gel ◽

High Yield ◽

Trace Impurities ◽

Fine Grained ◽

Oxide Powders ◽

Solid State Kinetics ◽

Transmission Electron ◽

Kinetics Of Formation

Powders and thin films of high-yield lanthanum hexaluminate (LaAl11O18) were prepared by a sol-gel route and compared with yields obtained by conventional hot-pressing of oxide powders. X-ray diffraction and transmission electron microscopy (TEM) were used to characterize powders and thin films deposited on TEM grids. While the solid-state kinetics of formation of LaA11O18 are known to be extremely sluggish, the yield of LaAl11O18 formed by the sol-gel route was much higher than that obtained by processing under similar conditions by solid-state reaction of elemental oxides. The development of a very fine grained microstructure at 1200 °C and a coarser, much more mature microstructure at 1450 °C, with strong texturing of the magnetoplumbite phase, was observed by TEM. Isolated grains of LaAlO3 were present in all powders and films. Trace impurities, introduced most likely as impurities in the initial alumina sol, appear to have segregated to both the grain boundaries and to the external surfaces of grains in as-prepared films.

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Ferroelectric Thin Films Via Sol-Gel Processing of Singlesource Precursors

MRS Proceedings ◽

10.1557/proc-310-357 ◽

1993 ◽

Vol 310 ◽

Cited By ~ 2

Author(s):

C.D. Chandler ◽

M.J. Hampden-Smith ◽

R.W. Schwartz

Keyword(s):

Thin Films ◽

Perovskite Phase ◽

Ferroelectric Properties ◽

Sol Gel ◽

Dip Coating ◽

Mixed Metal Oxide ◽

Mixed Metal ◽

Oxide Powders ◽

Metal Organic ◽

Gel Processing

AbstractThe use of single-source mixed metal-organic precursors specifically designed for the formation of crystalline perovskite phase mixed metal oxide powders has been investigated. Pyridine solutions of divalent metal α-hydroxycarboxylates of general empirical formula A(O2CCMe2OH)2 where A = Pb, Ca, Sr, Ba; Me = methyl, were designed to react with metal alkoxides, for example, Ti(O-i-Pr)4, with the elimination of two equivalents of alcohol to form species with fixed A:B stoichiometry of 1:1 according to the equation: A(O2CCMe2OH)2 + B(OR)4 → A(O2CCMe2O)2B(OR)2 + 2HOR. Hydrolysis of these compounds in pyridine produces clear solutions which on removal of the solvent in vacuo, yield yellow powders. These powders readily dissolve in ethanol to give solutions from which thin films can be formed either by dip-coating or spin coating. The crystallization behavior, composition and ferroelectric properties of these films is discussed. The crystallization of the films generally required substantially higher temperatures compared to powders obtained from the same precursor solutions.

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Pr Doped YBCO Films Produced by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-0946-hh09-09 ◽

2006 ◽

Vol 946 ◽

Author(s):

B. Craig Harrison ◽

Joseph W. Kell ◽

Paul N. Barnes ◽

Timothy J. Haugan ◽

Chakrapani V. Varanasi ◽

...

Keyword(s):

Mass Spectrometry ◽

Thin Films ◽

Pulsed Laser Deposition ◽

Secondary Ion Mass Spectrometry ◽

Full Range ◽

Pulsed Laser ◽

Laser Deposition ◽

Pinning Force ◽

Oxide Powders ◽

Secondary Ion

ABSTRACTPr doped YBa2Cu3O7-d targets with composition Y1-xPrxBa2Cu3O7-d where × = 0.0001, 0.001, 0.01, and 0.1 were prepared from oxide powders and were used to deposit thin films by pulsed laser deposition using conditions previously optimized for pure YBa2Cu3O7-d. The Pr dopant was found to be dispersed throughout the film by secondary ion mass spectrometry and found to have an increased density of nanoparticles on the surface. The pinning force of the doped samples was found to decrease with increasing concentration of Pr; however, at 0.01% concentration the doped film displayed a significant enhancement over pure YBa2Cu3O7-d for nearly the full range of 0 – 9 T.

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Liquid-Mix Synthesis of Oxide Powders and Thin Films Using A Starch-Based Polymer

MRS Proceedings ◽

10.1557/proc-346-109 ◽

1994 ◽

Vol 346 ◽

Author(s):

Lone-Wen F. Tai ◽

Harlan U. Anderson

Keyword(s):

Thin Films ◽

Nitric Acid ◽

Spin Coating ◽

Yttrium Aluminum Garnet ◽

Nitrate Solution ◽

Soluble Starch ◽

Single Step ◽

Water Soluble ◽

Organic Precursor ◽

Oxide Powders

ABSTRACTA commercially available water-soluble starch derivative was used as the sole organic precursor in the Liquid-Mix synthesis of mixed-cation oxide powders and thin films. The acidified polymer (by nitric acid) was able to complex metal ions through the carboxylate ligands. Loosely agglomerated fine powders as well as dense thin films of complex oxides have been prepared using the same type of polymer. Oxide powders of Cr-doped lanthanum aluminate and yttrium aluminum garnet both crystallized in a single step, without forming any intermediate or second phases, when the amorphous resin intermediates were calcined at 650°C and 750°C for 2 hours, respectively. It was demonstrated that nitric acid could effectively reduce the viscosity of the polymer-nitrate solution to make it suitable for spin coating process. Dense thin films of Y(8 mol%)-doped ZrO2 were formed on Si and A12O3 substrates by spin coating the polymeric solution and heating at temperatures below 1000°C.

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Copper Benzenetricarboxylate Metal–Organic Framework Nucleation Mechanisms on Metal Oxide Powders and Thin Films formed by Atomic Layer Deposition

ACS Applied Materials & Interfaces ◽

10.1021/acsami.6b01195 ◽

2016 ◽

Vol 8 (14) ◽

pp. 9514-9522 ◽

Cited By ~ 38

Author(s):

Paul C. Lemaire ◽

Junjie Zhao ◽

Philip S. Williams ◽

Howard J. Walls ◽

Sarah D. Shepherd ◽

...

Keyword(s):

Thin Films ◽

Atomic Layer Deposition ◽

Metal Oxide ◽

Metal Organic Framework ◽

Atomic Layer ◽

Oxide Powders ◽

Layer Deposition ◽

Nucleation Mechanisms ◽

Metal Organic ◽

Organic Framework

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The study of interfacial reactions of nickel thin films on GaAs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074616 ◽

1983 ◽

Vol 41 ◽

pp. 156-157

Author(s):

L.J. Chen ◽

Y.F. Hsieh

Keyword(s):

Thin Films ◽

Integrated Circuits ◽

Interfacial Reactions ◽

Metal Contacts ◽

Nickel Thin Films ◽

Thin Foils ◽

The Status ◽

Si Doped ◽

Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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Nucleation and Early Growth of Sputtered thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069570 ◽

1970 ◽

Vol 28 ◽

pp. 516-517

Author(s):

Dudley M. Sherman ◽

Thos. E. Hutchinson

Keyword(s):

Thin Films ◽

Electron Beam ◽

Ion Beam ◽

Ion Source ◽

Water Cooling ◽

Stages Of Growth ◽

Lens Assembly ◽

Microscope Technique ◽

Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

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