Microstructure of KTa[sub x]Nb[sub 1[minus]x]O[sub 3] thin films on MgO (100) single crystals

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb04620.x· OSTI ID:6889158

Nazeri, A; Kahn, M; Bender, B ^[1]; Allen, C ^[2]

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1. Naval Research Lab., Washington, DC (United States)
2. Lockheed Engineering and Sciences Co., Houston, TX (United States)

Thin KTa[sub x]Nb[sub 1[minus]x]O[sub 3] (KTN) films were prepared by deposition of sol-gel precursor solutions on MgO (100) single crystals. Crystal structure and microstructure of the films as a function of processing parameters, such as rate, duration, and temperature of post deposition heat treatment, were studied. Several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to analyzed the films. It was observed that slow heating of KTN films promotes pyrochlore crystallites while fast-firing of the films results in predominant formation of the perovskite phase. In slow-heated samples, TEM showed randomly oriented pyrochlore crystallites with a vermicular nanostructure of 10-30 nm with an interpenetrating porosity of the same range. In fast-fired samples, large perovskite pockets with pyrochlore crystallites scattered among them were seen. The large perovskite grains were on the order of 0.1--0.5 [mu]m, irregular in shape and porous. Transmission electron diffraction indicated these were single crystals, and ferro-electric domains were observed in them. Films of up to 1[mu]m thick were obtained by multiple deposition of the sol-gel KTN. Dense films were achieved when each layer was densified at 750 C for 2 h before the next layer was deposited.

• OSTI ID: 6889158
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:9; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NIOBIUM OXIDES
MICROSTRUCTURE
PHASE STUDIES
SOL-GEL PROCESS
POTASSIUM OXIDES
TANTALUM OXIDES
EXPERIMENTAL DATA
TEMPERATURE DEPENDENCE
ALKALI METAL COMPOUNDS
CHALCOGENIDES
DATA
INFORMATION
NIOBIUM COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
REFRACTORY METAL COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication