Anisotropic strain relaxation through prismatic and basal slip in α-(Al, Ga)2O3 on R-plane Al2O3
Pseudomorphic and partially relaxed layers of corundum phase (Al, Ga)2O3 epilayers on (01.2)-oriented Al2O3 fabricated by pulsed laser deposition (PLD) are investigated. An exact analytical (continuum elasticity) strain theory for rhombohedral heterostructures as a function of the two substrate orie...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2020-02-01
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| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/1.5144744 |
| Summary: | Pseudomorphic and partially relaxed layers of corundum phase (Al, Ga)2O3 epilayers on (01.2)-oriented Al2O3 fabricated by pulsed laser deposition (PLD) are investigated. An exact analytical (continuum elasticity) strain theory for rhombohedral heterostructures as a function of the two substrate orientation angles fits the strain state of pseudomorphic and relaxed samples very well. From reciprocal space maps and a quantitative analysis of x-ray diffraction peaks and tilts using the strain theory, it is concluded that in the present samples grown below 800 °C, plastic strain relaxation above the critical thickness occurs first through slip on the prismatic a-plane glide system and subsequently via the basal c-plane system. We also present a general PLD stoichiometry transfer model simultaneously explaining the epilayer alloy composition and growth rate in the entire composition range. |
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| ISSN: | 2166-532X |