Electron mobilities in SrTiO₃ and KTaO₃: Role of phonon anharmonicity, mass renormalization, and disorder

Autor(en)

Luigi Ranalli, Carla Verdi, Marios Zacharias, Jacky Even, Feliciano Giustino, Cesare Franchini

Abstrakt

Accurately predicting carrier mobility in strongly anharmonic solids necessitates a precise characterization of lattice dynamics as a function of temperature. We achieve consistency with experimental electron mobility data for bulk KTaO3 and SrTiO3 above 150 K by refining the Boltzmann transport equations. This refinement includes incorporating temperature-dependent anharmonic phonon eigenfrequencies and eigenmodes into the electron-phonon interaction tensor, while maintaining the derivatives of the Kohn-Sham potential as computed in density functional perturbation theory. Using efficient machine-learned force fields and the stochastic self-consistent harmonic approximation, we accurately compute the dynamical matrices. At room temperature, the calculated mobility for SrTiO3 exceeds experimental values by an order of magnitude, whereas the overestimation for KTaO3 is much less pronounced. This discrepancy is explained through the more significant electron mass renormalization near the conduction-band bottom due to anharmonic electron-phonon coupling and the presence of local disorder in SrTiO3.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

University of Queensland, Université de Rennes, University of Texas, Austin, Università di Bologna

Journal

Physical Review Materials

Band

8

Anzahl der Seiten

11

ISSN

2475-9953

DOI

https://doi.org/10.48550/arXiv.2407.18771

Publikationsdatum

10-2024

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik, 103043 Computational Physics

ASJC Scopus Sachgebiete

Allgemeine Materialwissenschaften, Physics and Astronomy (miscellaneous)

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/bf0584f4-492e-4a2d-ac15-ecc7109c22a6