Micrograph Library
Browse the libraryAdvanced searchSystemsCompositionsTechniquesKeywordsPhase diagramsHelpPreferencesAbout the micrograph libraryTerms of useContribute micrographs!FeedbackLinksCredits Print this page
Full Record for Micrograph 199
[304 KB]
View micrograph
.. in new window
View micrograph and record
.. in new window
You can also view and download the micrographs on Flickr
- Micrograph no
- 199
- Brief description
- BaTiO3 Temperature-stable dielectric capacitor
- Keywords
- alumina
, ceramic , engineering ceramic - Categories
- Ceramic
- System
- BaTiO3 + other oxides such as Nb2O5, Bi2O3
- Composition
- BaTiO3 95-97 (wt%)
- Standard codes
- Reaction
- Processing
- Fine oxide additives react with BaTiO3 powder forming a series of phases which act as the source for the dopants.
- Applications
- Temperature stable X7R capacitors in millions of electrical circuits.
- Sample preparation
- Grind, polish, ion thin and carbon coat.
- Technique
- Bright-field TEM
- Length bar
- 1 μm
- Further information
- The image shows a single representative grain within the polycrystalline ceramic. The core region shows ferroelectric domains from the pure, tetragonal BaTiO3 centre. The shell region contains Nb and Bi dopant which make it cubic, paraelectric and also stacking faults associated with their presence. The heterogeneous nature of the microstructure confers the temperature stability on the ceramic.
- Contributor
- Prof W E Lee
- Organisation
- Department of Engineering Materials, University of Sheffield
- Date
- 02/09/02
- Licence for re-use
Attribution-NonCommercial-ShareAlike 4.0 International