TY - JOUR
T1 - Epitaxy of tungsten on polycrystalline molybdenum using chemical vapor transport deposition technology
AU - Xie, Yajuan
AU - Tan, Chengwen
AU - Yu, Xiaodong
AU - Zhu, Hao
AU - Nie, Zhihua
N1 - Publisher Copyright:
© 2022
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Polycrystalline tungsten (W) coatings were deposited on molybdenum (Mo) polycrystalline substrates via chemical vapor transport deposition (CVTD). The structural characterization of the samples indicates an epitaxial relationship between W and Mo; however, there are voids at the W–Mo interface, and the number of voids increases as the temperature decreases. Further, the deposition rate of W coatings decreases with decreasing temperature and pressure. The grains of the coatings deposited at 1420–1590 K have diverse orientations when the pressure is 250 Pa; however, the [1 0 0]-oriented grains are the majority. When the temperature reaches 1590 K, penetration twins form inside the coatings as the pressure decreases from 250 to 50 Pa. Further, the coating grains have no obvious preferred orientation with decreasing pressure. Compositional penetration was discovered at the W–Mo interface, and the penetration depth of Mo into W decreased with decreasing temperature. This study analyzes the competitive growth of W grains and the formation of penetration twins according to influence of the environment on the growth process. The voids and compositional penetration at the W–Mo interface are caused by the diffusion at the defects; thus, the distribution of the diffusion sites can demonstrate the perfection of the epitaxial W–Mo coherent interface. This study contributes to the structural regulation of epitaxial W on Mo.
AB - Polycrystalline tungsten (W) coatings were deposited on molybdenum (Mo) polycrystalline substrates via chemical vapor transport deposition (CVTD). The structural characterization of the samples indicates an epitaxial relationship between W and Mo; however, there are voids at the W–Mo interface, and the number of voids increases as the temperature decreases. Further, the deposition rate of W coatings decreases with decreasing temperature and pressure. The grains of the coatings deposited at 1420–1590 K have diverse orientations when the pressure is 250 Pa; however, the [1 0 0]-oriented grains are the majority. When the temperature reaches 1590 K, penetration twins form inside the coatings as the pressure decreases from 250 to 50 Pa. Further, the coating grains have no obvious preferred orientation with decreasing pressure. Compositional penetration was discovered at the W–Mo interface, and the penetration depth of Mo into W decreased with decreasing temperature. This study analyzes the competitive growth of W grains and the formation of penetration twins according to influence of the environment on the growth process. The voids and compositional penetration at the W–Mo interface are caused by the diffusion at the defects; thus, the distribution of the diffusion sites can demonstrate the perfection of the epitaxial W–Mo coherent interface. This study contributes to the structural regulation of epitaxial W on Mo.
KW - A1. Characterization
KW - A1. Crystal structure
KW - A1. Interface
KW - A3. Chemical vapor transport deposition
KW - A3. Vapor phase epitaxy
KW - B1. Polycrystalline tungsten coatings
UR - http://www.scopus.com/inward/record.url?scp=85144385166&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2022.127046
DO - 10.1016/j.jcrysgro.2022.127046
M3 - Article
AN - SCOPUS:85144385166
SN - 0022-0248
VL - 603
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
M1 - 127046
ER -