The effects of solution chemistry on the sol-gel processing of lithium niobate

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Ceramic Transactions; (United States)

OSTI ID:7018244

Eichorst, D J; Payne, D A ^[1]; Wragg, A N.A. ^[2]

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1. Univ. of Illinois, Urbana (United States)
2. Univ. of Leeds (United Kingdom)

Lithium niobate powders and films were prepared by sol-gel methods. A mixed-metal alkoxide, lithium niobium methoxy-ethoxide, was synthesized and determined to be suitable for the preparation of gels and the spin-casting of thin-layers. Formation of the alkoxide complex was studied by multinuclear NMR methods. The influence of water, nitric acid and ammonium hydroxide on crystallization behavior and film microstructure was determined. Bulk gels had an exothermic decomposition at 250C, with crystallization at [approximately] 470C for acidic gels and [approximately]490C for basic gels. The crystallization temperatures were approximately independent of the original water content. Lithium niobate films on silicon (111) crystallized at 650C in air, with well-developed microstructures by 800C (30 min). Acidic films were porous, whereas basic films were dense (99%). The grain size for acidic films (0.3 [mu]m) was somewhat finer than for basic films (0.5 [mu]m). Both grain size and density were essentially independent of water content for acid and base additions. However, films without additions exhibited an increase in density and grain size with increasing water content. The results suggest the use of ammonium hydroxide with low water content for the formation of dense LiNbO[sub 3] layers.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 7018244
• Journal Information: Ceramic Transactions; (United States), Vol. 11
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
LITHIUM COMPOUNDS
CHEMICAL PREPARATION
NIOBATES
ALKOXIDES
AMMONIUM HYDROXIDES
CHEMICAL REACTION KINETICS
CRYSTALLIZATION
DECOMPOSITION
FILMS
GELS
GRAIN SIZE
MICROSTRUCTURE
NITRIC ACID
NUCLEAR MAGNETIC RESONANCE
POWDERS
QUANTITY RATIO
SOLS
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
WATER
ALKALI METAL COMPOUNDS
AMMONIUM COMPOUNDS
CHEMICAL REACTIONS
COLLOIDS
CRYSTAL STRUCTURE
DISPERSIONS
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
KINETICS
MAGNETIC RESONANCE
NIOBIUM COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
RESONANCE
SIZE
SYNTHESIS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS
360601* - Other Materials- Preparation & Manufacture