Influence of nanostructure formation on the crystal structure and morphology of epitaxially grown Gd2O3 on Si(001)
Gribisch, Philipp LU
; Schmidt, Jan
; Osten, Hans-jörg
and Fissel, Andreas
(2019)
In Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials
75(1).
p.59-70
- Abstract
- The influence of growth conditions on the layer orientation, domain structure and crystal structure of gadolinium oxide (Gd2O3) on silicon (001) has been investigated. Gd2O3 was grown at low (250°C) and high (850°C) temperatures with different oxygen partial pressure as well as a temperature ramp up during growth. At low temperature, the cubic bixbyite type of crystal structure with space group Ia{\bar 3} was grown at low oxygen partial pressure. The layers consist of two domains oriented orthogonal to each other. The epitaxial relationships for the two domains were found to be Gd2O3(110)[001]||Si(001)[110] and Gd2O3(110)[001]||Si(001)[{\bar 1}10],... (More)
- The influence of growth conditions on the layer orientation, domain structure and crystal structure of gadolinium oxide (Gd2O3) on silicon (001) has been investigated. Gd2O3 was grown at low (250°C) and high (850°C) temperatures with different oxygen partial pressure as well as a temperature ramp up during growth. At low temperature, the cubic bixbyite type of crystal structure with space group Ia{\bar 3} was grown at low oxygen partial pressure. The layers consist of two domains oriented orthogonal to each other. The epitaxial relationships for the two domains were found to be Gd2O3(110)[001]||Si(001)[110] and Gd2O3(110)[001]||Si(001)[{\bar 1}10], respectively. Applying additional oxygen during growth results in a change in crystal and domain structures of the grown layer into the monoclinic Sm2O3-type of structure with space group C2/m with (20\bar 1) orientation and mainly two orthogonal domains with the epitaxial relationship Gd2O3(20\bar 1)[010]||Si(100)⟨110⟩ and a smooth surface morphology. Some smaller areas have two intermediate azimuthal orientations between these variants, which results in a six-domain structure. The change in crystal structure can be understood based on the Gibbs–Thomson effect caused by the initial nucleation of nanometre-sized islands and its variation in diameter with a change in growth conditions. The crystal structure remains stable even against a temperature ramp up during growth. The layers grown at high temperature exhibit a nanowire-like surface morphology, where the nanowires have a cubic crystal structure and are aligned orthogonal to each other along the ⟨110⟩ in-plane directions. An increase in oxygen supply results in a reduced length and increased number of nanowires due to lower adatom mobility. The results clearly indicate that both kinetic and thermodynamic factors have a strong impact on the crystal structure, epitaxial relationship and morphology of the grown layers. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/73905258-9f2b-4d9b-93d1-20ded50608fa
- author
- Gribisch, Philipp
LU
; Schmidt, Jan
; Osten, Hans-jörg
and Fissel, Andreas
- publishing date
- 2019-02-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials
- volume
- 75
- issue
- 1
- pages
- 59 - 70
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:85061321574
- ISSN
- 2052-5206
- DOI
- 10.1107/S2052520618017869
- language
- English
- LU publication?
- no
- id
- 73905258-9f2b-4d9b-93d1-20ded50608fa
- date added to LUP
- 2022-12-09 15:21:40
- date last changed
- 2024-05-20 04:01:05
@article{73905258-9f2b-4d9b-93d1-20ded50608fa,
abstract = {{The influence of growth conditions on the layer orientation, domain structure and crystal structure of gadolinium oxide (Gd<sub>2</sub>O<sub>3</sub>) on silicon (001) has been investigated. Gd<sub>2</sub>O<sub>3</sub> was grown at low (250°C) and high (850°C) temperatures with different oxygen partial pressure as well as a temperature ramp up during growth. At low temperature, the cubic bixbyite type of crystal structure with space group Ia{\bar 3} was grown at low oxygen partial pressure. The layers consist of two domains oriented orthogonal to each other. The epitaxial relationships for the two domains were found to be Gd<sub>2</sub>O<sub>3</sub>(110)[001]||Si(001)[110] and Gd<sub>2</sub>O<sub>3</sub>(110)[001]||Si(001)[{\bar 1}10], respectively. Applying additional oxygen during growth results in a change in crystal and domain structures of the grown layer into the monoclinic Sm<sub>2</sub>O<sub>3</sub>-type of structure with space group C2/<i>m</i> with (20\bar 1) orientation and mainly two orthogonal domains with the epitaxial relationship Gd<sub>2</sub>O<sub>3</sub>(20\bar 1)[010]||Si(100)⟨110⟩ and a smooth surface morphology. Some smaller areas have two intermediate azimuthal orientations between these variants, which results in a six-domain structure. The change in crystal structure can be understood based on the Gibbs–Thomson effect caused by the initial nucleation of nanometre-sized islands and its variation in diameter with a change in growth conditions. The crystal structure remains stable even against a temperature ramp up during growth. The layers grown at high temperature exhibit a nanowire-like surface morphology, where the nanowires have a cubic crystal structure and are aligned orthogonal to each other along the ⟨110⟩ in-plane directions. An increase in oxygen supply results in a reduced length and increased number of nanowires due to lower adatom mobility. The results clearly indicate that both kinetic and thermodynamic factors have a strong impact on the crystal structure, epitaxial relationship and morphology of the grown layers.}},
author = {{Gribisch, Philipp and Schmidt, Jan and Osten, Hans-jörg and Fissel, Andreas}},
issn = {{2052-5206}},
language = {{eng}},
month = {{02}},
number = {{1}},
pages = {{59--70}},
publisher = {{Wiley-Blackwell}},
series = {{Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials}},
title = {{Influence of nanostructure formation on the crystal structure and morphology of epitaxially grown Gd<sub>2</sub>O<sub>3</sub> on Si(001)}},
url = {{http://dx.doi.org/10.1107/S2052520618017869}},
doi = {{10.1107/S2052520618017869}},
volume = {{75}},
year = {{2019}},
}