In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 36, No. 23 ( 2021-12-14), p. 4816-4831
Kurzfassung:
Pseudomorphic and relaxed $$\alpha$$ α -(Al $$_x$$ x Ga $$_{1-x}$$ 1 - x ) $$_2$$ 2 O $$_3$$ 3 thin films are grown by combinatorial pulsed laser deposition in the entire composition range on prismatic a- and m-plane $$\alpha$$ α -Al $$_2$$ 2 O $$_3$$ 3 substrates. Pseudomorphic growth on m-plane sapphire has been achieved for $$x \ge 0.45$$ x ≥ 0.45 . A distinct difference between the a- and m-epitaxial plane is observed in reciprocal space map measurements being in agreement with continuum elasticity theory for rhombohedral heterostructures. While pseudomorphic layers on m-plane sapphire show a pronounced shear strain $$e'_5$$ e 5 ′ along the c -axis direction, relaxed layers exhibit a global lattice tilt in the same direction. Both effects are not present on the a-epitaxial plane. Out-of-plane lattice constants as well as $$e'_5$$ e 5 ′ are modeled as function of x employing elasticity theory, confirming theoretical values of the elastic stiffness tensor for $$\alpha$$ α -Ga $$_2$$ 2 O $$_3$$ 3 , especially the non-zero value of the $$C_{14}$$ C 14 component. Possible pyramidal slip systems for strain relaxation in c -axis direction are examined to explain and numerically model the difference in lattice tilt for the two substrate orientations. Graphic abstract
Materialart:
Online-Ressource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/s43578-021-00375-3
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2021
ZDB Id:
54876-5
ZDB Id:
2015297-8
Permalink