Lithium tantalate

Lithium tantalate (LiTaO₃) is a perovskite which possesses unique optical, piezoelectric and pyroelectric properties which make it valuable for nonlinear optics, passive infrared sensors such as motion detectors, terahertz generation and detection, surface acoustic wave applications, cell phones and possibly pyroelectric nuclear fusion. Considerable information is available from commercial sources about this salt.

Lithium tantalate

__ Li^+     __ Ta^5+     __ O^2−
Names
IUPAC name Lithium tantalate
Other names Lithium Metatantalate
Identifiers
CAS Number	12031-66-2^Y
ECHA InfoCard	100.031.584
PubChem CID	159405
RTECS number	WW55470000
CompTox Dashboard (EPA)	DTXSID60923322
Properties
Chemical formula	LiTaO3
Molar mass	235.887 g/mol
Density	7.46 g/cm^3, solid
Melting point	1,650 °C (3,000 °F; 1,920 K)
Solubility in water	Insoluble in water
Structure
Crystal structure	Space group R3c
Lattice constant	a = 515.43 pm, c = 1378.35 pm[1]
Hazards
Main hazards	Acute Toxicity: Oral, Inhalation, Dermal
Safety data sheet	See: data page http://www.samaterials.com/pdf/Lithium-Tantalate-Wafers-(LiTaO3-Wafers)-sds.pdf
Related compounds
Other anions	LiNbO3
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is ^YN ?)
Infobox references

Pyroelectric fusion

Main article: Pyroelectric fusion

According to an April 2005 Nature article, Brian Naranjo, Jim Gimzewski and Seth Putterman at UCLA applied a large temperature difference to a lithium tantalate crystal producing a large enough charge to generate and accelerate a beam of deuterium nuclei into a deuteriated target resulting in the production of a small flux of helium-3 and neutrons through nuclear fusion without extreme heat or pressure.[2] Their results have been replicated.

It is unlikely to be useful for electricity generation since the energy required to produce the fusion reactions exceeded the energy produced by them. It is thought that the technique might be useful for small neutron generators, especially if the deuterium beam is replaced by a tritium one. Comparing this with the electrostatic containment of ionic plasma to achieve fusion in a "fusor" or other IEC, this method focuses electrical acceleration to a much smaller non-ionized deuterium target without heat.

Water and freezing

A scientific paper published in February 2010 shows a difference in the temperature and mechanism of freezing water to ice, depending on the charge applied to a surface of pyroelectric LiTaO₃ crystals.[3]

References

1. Abrahams, S.C; Bernstein, J.L (1967). "Ferroelectric lithium tantalate—1. Single crystal X-ray diffraction study at 24°C". Journal of Physics and Chemistry of Solids. 28 (9): 1685. doi:10.1016/0022-3697(67)90142-4.
2. B. Naranjo, J.K. Gimzewski & S. Putterman (2005). "Observation of nuclear fusion driven by a pyroelectric crystal". Nature. 434 (7037): 1115–1117. doi:10.1038/nature03575. PMID 15858570.
3. D. Ehre; E. Lavert; M. Lahav; I. Lubomirsky (2010). "Water Freezes Differently on Positively and Negatively Charged Surfaces of Pyroelectric Materials". Science. 327 (5966): 672–675. doi:10.1126/science.1178085. PMID 20133568.

Further reading

• "Fusion seen in table-top experiment" Physics Web, 27 April 2005