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Nucleation Control in Physical Vapor Transport Growth of AlN Single Crystals on Polycrystal Tungsten Substrates.
- Source :
-
Materials Science / Medziagotyra . 2020, Vol. 26 Issue 2, p139-142. 4p. - Publication Year :
- 2020
-
Abstract
- The improved resistively-heated furnace with two heaters established a vertical thermal gradient to control nucleation during AlN single crystals Physical Vapor Transport (PVT) growth on polycrystal tungsten substrates. During the high temperature (> 1850 °C) heating process, the reverse temperature field (i.e., the temperature difference between the sublimation zone and the crystalline zone ΔT < 0) was obtained to reduce the number of nuclei on the tungsten substrate. During growth, the proper positive values of ΔT T were chosen to content the supersaturation values (0.25 < S < 0.3). The reverse temperature condition during high temperature (> 1850 °C) cooling was fulfilled to avoid recrystallization on grown AlN crystal. AlN single crystals made through the method were characterized by X-ray diffractions (XRD) and Raman spectroscopy. [ABSTRACT FROM AUTHOR]
- Subjects :
- *SINGLE crystals
*TUNGSTEN
*NUCLEATION
*GASES
*VAPORS
*TUNGSTEN alloys
Subjects
Details
- Language :
- English
- ISSN :
- 13921320
- Volume :
- 26
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Materials Science / Medziagotyra
- Publication Type :
- Academic Journal
- Accession number :
- 141503217
- Full Text :
- https://doi.org/10.5755/j01.ms.26.2.21575