Lithium tantalate
Crystal structure | ||||||||||||||||
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__ Li + __ Ta 5+ __ O 2− | ||||||||||||||||
Crystal system | ||||||||||||||||
Space group |
R 3 c (No. 161) |
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General | ||||||||||||||||
Surname | Lithium tantalate | |||||||||||||||
other names |
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Ratio formula | LiTaO 3 | |||||||||||||||
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properties | ||||||||||||||||
Molar mass | 235.89 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
7.4564 g cm −3 |
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Melting point |
1650 ° C |
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Refractive index |
2.183 |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
Lithium tantalate is a chemical compound from the group of tantalates .
Occurrence
A lithium tantalate occurs naturally in the form of the mineral lithiowodginite , although this has the formula LiTa 3 O 8 and thus represents a different chemical compound.
Extraction and presentation
Lithium tantalate can be obtained by reacting lithium carbonate with tantalum (V) oxide .
properties
Lithium tantalate is a solid. It has a trigonal crystal structure with the space group R 3 c (space group no. 161) and a specific heat capacity of 424 J / (K kg). Like lithium niobate, it is ferroelectric, linear electro-optic, piezoelectric, and pyroelectric . Lithium tantalate is weakly birefringent .
use
Lithium tantalate crystals are used as an electro-optical Q - switch and substrate for integrated optics, sensors and frequency converters. They are mainly used to implement SAW components . A pyroelectric crystal made of lithium tantalate was used as a voltage source in connection with investigations into pyrofusion .
Individual evidence
- ↑ a b c d e Korth crystals: lithium tantalate
- ↑ a b data sheet lithium tantalate, ≥99.99% from Sigma-Aldrich , accessed on January 10, 2012 ( PDF ).
- ↑ MinDat: Lithiowodginite
- ↑ a b Joachim Frühauf: Materials in microtechnology . Carl Hanser Verlag, 2005, ISBN 978-3-446-22557-2 ( page 77 in the Google book search).
- ↑ Manfred Müller: Interaction of light with ferroelectric domains in lithium niobate and lithium tantalate crystals . Bonn 2004, DNB 971832986 , urn : nbn: de: hbz: 5N-03854 (dissertation, University of Bonn).
- ↑ Eugene Hecht: Optics . Walter de Gruyter GmbH & Co KG, 2018, ISBN 978-3-11-052670-7 ( limited preview in the Google book search).
- ↑ S. Huband, DS Keeble u. a .: Relationship between the structure and optical properties of lithium tantalate at the zero-birefringence point. In: Journal of Applied Physics. 121, 2017, p. 024102, doi : 10.1063 / 1.4973685 .
- ↑ Nuclear fusion in small format. In: Neue Zürcher Zeitung . May 4, 2005, accessed September 5, 2017 .
- ^ MJ Saltmarsh: Technology: Warm fusion . In: Nature . tape 434 , no. 7037 , April 2005, p. 1077-1080 , doi : 10.1038 / 4341077a .
- ↑ B. Naranjo, JK Gimzewski, p Putterman: Observation of nuclear fusion driven by a pyroelectric crystal . In: Nature . tape 434 , no. 7037 , April 2005, p. 1115–1117 , doi : 10.1038 / nature03575 .