Hydrothermal phase stability study of Li{sub 2}B{sub 4}O{sub 7}
- Department of Engineering Physics, Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson AFB, OH 45433-7765 (United States)
- Air Force Research Laboratory Sensors Directorate, 2241 Avionics Circle, Bldg 600, Wright-Patterson AFB, OH 45433-7765 (United States)
Growth of Li{sub 2}B{sub 4}O{sub 7} by the hydrothermal method was attempted in 10{sup −6} M LiOH, by both spontaneous nucleation and transport growth. Li{sub 2}B{sub 4}O{sub 7} grew out of the first spontaneous nucleation reaction, while the seed dissolved and γ-LiBO{sub 2} formed during the transport growth reactions. A species thermodynamic stability study showed that γ-LiBO{sub 2} formed exclusively from 350 °C to 550 °C, and Li{sub 3}B{sub 5}O{sub 8}(OH){sub 2} was observed at 250 °C; Li{sub 2}B{sub 4}O{sub 7} was not observed. A solubility study on Li{sub 2}B{sub 4}O{sub 7} did not achieve equilibrium conditions, but did demonstrate that γ-LiBO{sub 2} is significantly more thermodynamically stable than Li{sub 2}B{sub 4}O{sub 7} under the tested conditions. Formation of Li{sub 2}B{sub 4}O{sub 7} hydrothermally was shown to result from kinetic growth. - Graphical abstract: Every boron in lithium γ-metaborate is tetrahedrally coordinated with oxygen, and each tetrahedron is linked to four other tetrahedrons, creating a strong B-O lattice surrounding the lithium atoms. - Highlights: • Li{sub 2}B{sub 4}O{sub 7} was grown hydrothermally via spontaneous nucleation in 10{sup −6} M LiOH. • γ-LiBO{sub 2} formed from 350 °C to 550 °C and Li{sub 3}B{sub 5}O{sub 8}(OH){sub 2} was observed at 250 °C. • A solubility study showed γ-LiBO{sub 2} to be more thermodynamically stable than Li{sub 2}B{sub 4}O{sub 7}. • Hydrothermal formation of Li{sub 2}B{sub 4}O{sub 7} was shown to result from kinetic growth.
- OSTI ID:
- 22443374
- Journal Information:
- Journal of Solid State Chemistry, Vol. 216; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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