Abstract
We report β-NMR measurements in Bi2Se3:Ca and Bi2Te3:Mn single crystals using 8Li+ implanted to depths on the order of 100 nm. Above ∼200K, spin-lattice relaxation reveals diffusion of 8Li+, with activation energies of ∼0.4eV (∼0.2eV) in Bi2Se3:Ca (Bi2Te3:Mn). At lower temperatures, the NMR properties are those of a heavily doped semiconductor in the metallic limit, with Korringa relaxation and a small, negative, temperature-dependent Knight shift in Bi2Se3:Ca. From this, we make a detailed comparison with the isostructural tetradymite Bi2Te2Se [McFadden, Phys. Rev. B 99, 125201 (2019)2469-995010.1103/PhysRevB.99.125201]. In the magnetic Bi2Te3:Mn, the effects of the dilute Mn moments predominate, but remarkably the 8Li signal is not wiped out through the magnetic transition at 13 K, with a prominent critical peak in the spin-lattice relaxation that is suppressed in a high applied field. This detailed characterization of the 8Li NMR response is an important step toward using depth-resolved β-NMR to study the low-energy properties of the chiral topological surface state in the Bi2Ch3 tetradymite topological insulator.
Recommended Citation
R. M. McFadden et al., "Local Electronic and Magnetic Properties of the Doped Topological Insulators Bi₂Se₃:Ca and Bi₂Te₃:Mn Investigated using Ion-implanted ⁸Li β-NMR," Physical Review B, vol. 102, no. 23, American Physical Society (APS), Dec 2020.
The definitive version is available at https://doi.org/10.1103/PhysRevB.102.235206
Department(s)
Physics
International Standard Serial Number (ISSN)
2469-9950; 2469-9969
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2020 American Physical Society (APS), All rights reserved.
Publication Date
28 Dec 2020
