@article{06aaa38b73a54dab8e7215533397d419,
title = "Strain and stress relationships for optical phonon modes in monoclinic crystals with +¦-Ga2 O3 as an example",
abstract = "Strain-stress relationships for physical properties are of interest for heteroepitaxial material systems, where strain and stress are inherent due to thermal expansion and lattice mismatch. We report linear perturbation theory strain and stress relationships for optical phonon modes in monoclinic crystals for strain and stress situations which maintain the monoclinic symmetry of the crystal. By using symmetry group analysis and phonon frequencies obtained under various deformation scenarios from density-functional perturbation theory calculations on +¦-Ga2O3, we obtain four strain and four stress potential parameters for each phonon mode. We demonstrate that these parameters are sufficient to describe the frequency shift of the modes regardless of the stress or strain pattern which maintain the monoclinic symmetry of the crystal. The deformation potentials can be used together with experimentally determined phonon frequency parameters from Raman or infrared spectroscopy to evaluate the state of strain or stress of +¦-Ga2O3, for example, in epitaxial heterostructures.",
author = "R. Korlacki and M. Stokey and A. Mock and S. Knight and A. Papamichail and V. Darakchieva and M. Schubert",
note = "Funding Information: This work was supported in part by the National Science Foundation under Award No. DMR 1808715, by Air Force Office of Scientific Research under Award No.FA9550-18-1-0360, by the Nebraska Materials Research Science and Engineering Center under Award No.DMR 1420645, the Swedish Governmental Agency for Innovation Systems (VINNOVA) under the Competence Center Program Grant No. 2016-05190, the Swedish Research Council VR Award No. 2016-00889, the Swedish Foundation for Strategic Research Grants No. RIF14-055 and No. EM16-0024, by the Knut and Alice Wallenberg Foundation supported grant “Wide-bandgap semiconductors for next generation quantum components,” and by the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link{\"o}ping University, Faculty Grant SFO Mat LiU No. 2009-00971. M.S. acknowledges the University of Nebraska Foundation and the J. A. Woollam Foundation for financial support. This research was performed with support to A.M. from an NRC Research Associateship award at the U.S. Naval Research Laboratory. DFT calculations were in part performed at the Holland Computing Center of the University of Nebraska, which receives support from the Nebraska Research Initiative. The authors gratefully acknowledge a thorough reading of the manuscript and many insightful comments by the reviewer. Funding Information: This work was supported in part by the National Science Foundation under Award No. DMR 1808715, by Air Force Office of Scientific Research under Award No.FA9550-18-1-0360, by the Nebraska Materials Research Science and Engineering Center under Award No.DMR 1420645, the Swedish Governmental Agency for Innovation Systems (VINNOVA) under the Competence Center Program Grant No. 2016-05190, the Swedish Research Council VR Award No. 2016-00889, the Swedish Foundation for Strategic Research Grants No. RIF14-055 and No. EM16-0024, by the Knut and Alice Wallenberg Foundation supported grant {"}Wide-bandgap semiconductors for next generation quantum components,{"} and by the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link+?ping University, Faculty Grant SFO Mat LiU No. 2009-00971. M.S. acknowledges the University of Nebraska Foundation and the J. A. Woollam Foundation for financial support. This research was performed with support to A.M. from an NRC Research Associateship award at the U.S. Naval Research Laboratory. DFT calculations were in part performed at the Holland Computing Center of the University of Nebraska, which receives support from the Nebraska Research Initiative. The authors gratefully acknowledge a thorough reading of the manuscript and many insightful comments by the reviewer. Publisher Copyright: {\textcopyright} 2020 American Physical Society.",
year = "2020",
month = nov,
day = "12",
doi = "10.1103/PhysRevB.102.180101",
language = "English (US)",
volume = "102",
journal = "Physical Review B-Condensed Matter",
issn = "2469-9950",
publisher = "American Physical Society",
number = "18",
}