Solubility and dissolution kinetics of GaN in supercritical ammonia in presence of ammonoacidic and ammonobasic mineralizers

Journal article
(Original article)


Publication Details

Author(s): Schimmel S, Koch M, Macher P, Kimmel AC, Steigerwald T, Alt N, Schlücker E, Wellmann P
Journal: Journal of Crystal Growth
Publisher: Elsevier B.V.
Publication year: 2017
Volume: 479
Pages range: 59-66
ISSN: 0022-0248
Language: English


Abstract


Solubility and dissolution kinetics of GaN are investigated, as they represent essential parameters for ammonothermal crystal growth of GaN. In situ X-ray imaging is applied to monitor the dissolving crystal. Both ammonoacidic and ammonobasic conditions are investigated. Compared to NH4F, the dissolution is generally much slower using NaN3 mineralizer, leading to a much longer time needed to establish a saturated solution. The solubility of GaN at 540 °C and 260 MPa in supercritical ammonia with a molar concentration

of NaN3 of 0.72 mmol/ml is determined to be 0.15 ± 0.01 mol%. This suggest a severe

refinement of raw gravimetric literature data also for alkali metal based mineralizers, as we reported previously for ammonium halide mineralizers. The order of magnitude is in good agreement with refined gravimetric solubility data (Griffiths et al., 2016). The apparent discrepancy between the literature and this work regarding the temperature range in which retrograde solubility occurs is discussed. A possible reason for the occurrence of retrograde solubility at high temperatures is described. The paper is complemented by a section pointing out and partially quantifying potential, reactor-material-dependent sources of errors.



FAU Authors / FAU Editors

Alt, Nicolas
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Kimmel, Anna-Carina
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Koch, Martina
Lehrstuhl für Elektronische Bauelemente
Macher, Philipp
Lehrstuhl für Elektronische Bauelemente
Schimmel, Saskia
Professur für Werkstoffwissenschaften (Werkstoffe der Elektrotechnik)
Schlücker, Eberhard Prof. Dr.-Ing.
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Steigerwald, Thomas
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Wellmann, Peter Prof. Dr.-Ing.
Professur für Werkstoffwissenschaften (Werkstoffe der Elektrotechnik)


How to cite

APA:
Schimmel, S., Koch, M., Macher, P., Kimmel, A.-C., Steigerwald, T., Alt, N.,... Wellmann, P. (2017). Solubility and dissolution kinetics of GaN in supercritical ammonia in presence of ammonoacidic and ammonobasic mineralizers. Journal of Crystal Growth, 479, 59-66. https://dx.doi.org/10.1016/j.jcrysgro.2017.09.027

MLA:
Schimmel, Saskia, et al. "Solubility and dissolution kinetics of GaN in supercritical ammonia in presence of ammonoacidic and ammonobasic mineralizers." Journal of Crystal Growth 479 (2017): 59-66.

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Last updated on 2018-07-11 at 13:50