Infrared dielectric functions and Brillouin zone center phonons of
(2022) In Physical Review Materials 6(1).- Abstract
We determine the anisotropic dielectric functions of rhombohedral α-Ga2O3 by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high-frequency and static dielectric constants. We perform density functional theory computations and determine the phonon dispersion for all branches in the Brillouin zone, and we derive all phonon mode parameters at the Brillouin zone center including Raman-active, infrared-active, and silent modes. Excellent agreement is obtained between our experimental and computation results as well as among all previously reported partial information from experiment and theory.... (More)
We determine the anisotropic dielectric functions of rhombohedral α-Ga2O3 by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high-frequency and static dielectric constants. We perform density functional theory computations and determine the phonon dispersion for all branches in the Brillouin zone, and we derive all phonon mode parameters at the Brillouin zone center including Raman-active, infrared-active, and silent modes. Excellent agreement is obtained between our experimental and computation results as well as among all previously reported partial information from experiment and theory. We also compute the same information for α-Al2O3, the binary parent compound for the emerging alloy of α-(AlxGa1−x)2O3, and use results from previous investigations [Schubert, Tiwald, and Herzinger, Phys. Rev. B 61, 8187 (2000)10.1103/PhysRevB.61.8187] to compare all properties among the two isostructural compounds. From both experimental and theoretical investigations, we compute the frequency shifts of all modes between the two compounds. Additionally, we calculate overlap parameters between phonon mode eigenvectors and discuss the possible evolution of all phonon modes into the ternary alloy system and whether modes may form single-mode or more complex mode behaviors.
(Less)
- author
- publishing date
- 2022-01
- type
- Contribution to journal
- publication status
- published
- in
- Physical Review Materials
- volume
- 6
- issue
- 1
- article number
- 014601
- publisher
- American Physical Society
- external identifiers
-
- scopus:85122851669
- ISSN
- 2475-9953
- DOI
- 10.1103/PhysRevMaterials.6.014601
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2022 American Physical Society
- id
- 6702afc3-8659-4578-a932-5fc26a79e32f
- date added to LUP
- 2022-04-19 14:39:17
- date last changed
- 2022-07-06 15:22:50
@article{6702afc3-8659-4578-a932-5fc26a79e32f, abstract = {{<p>We determine the anisotropic dielectric functions of rhombohedral α-Ga2O3 by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high-frequency and static dielectric constants. We perform density functional theory computations and determine the phonon dispersion for all branches in the Brillouin zone, and we derive all phonon mode parameters at the Brillouin zone center including Raman-active, infrared-active, and silent modes. Excellent agreement is obtained between our experimental and computation results as well as among all previously reported partial information from experiment and theory. We also compute the same information for α-Al2O3, the binary parent compound for the emerging alloy of α-(AlxGa1−x)2O3, and use results from previous investigations [Schubert, Tiwald, and Herzinger, Phys. Rev. B 61, 8187 (2000)10.1103/PhysRevB.61.8187] to compare all properties among the two isostructural compounds. From both experimental and theoretical investigations, we compute the frequency shifts of all modes between the two compounds. Additionally, we calculate overlap parameters between phonon mode eigenvectors and discuss the possible evolution of all phonon modes into the ternary alloy system and whether modes may form single-mode or more complex mode behaviors.</p>}}, author = {{Stokey, Megan and Korlacki, Rafał and Hilfiker, Matthew and Knight, Sean and Richter, Steffen and Darakchieva, Vanya and Jinno, Riena and Cho, Yongjin and Xing, Huili Grace and Jena, Debdeep and Oshima, Yuichi and Khan, Kamruzzaman and Ahmadi, Elaheh and Schubert, Mathias}}, issn = {{2475-9953}}, language = {{eng}}, number = {{1}}, publisher = {{American Physical Society}}, series = {{Physical Review Materials}}, title = {{Infrared dielectric functions and Brillouin zone center phonons of}}, url = {{http://dx.doi.org/10.1103/PhysRevMaterials.6.014601}}, doi = {{10.1103/PhysRevMaterials.6.014601}}, volume = {{6}}, year = {{2022}}, }