TY - JOUR

T1 - Chemical Composition Dependent Raman Scattering Spectroscopy of MBE Grown Manganese - Based Bismuth Telluride Topological Insulator Thin Films

AU - Kumar, N.

AU - Ishchenko, Denis V

AU - Milekhin, Ilya A

AU - Kyrova, Ekaterina D

AU - Fedosenko, Evgeny V

AU - Milekhin, Alexander G

AU - Tereshchenko, Oleg E

N1 - Chemical Composition Dependent Raman Scattering Spectroscopy of MBE Grown Manganese-Based Bismuth Telluride Topological Insulator Thin Films / N. Kumar, D. V. Ishchenko, I. A. Milekhin [et al.] // Journal of Raman Spectroscopy. – 2025. – Vol. 56, No. 5. – P. 409-419. – DOI 10.1002/jrs.6779. The work has been partly supported by the grant from Ministry of science and higher education of Russia FSUS-2024-0020 and shared research center VTAN at NSU. The authors acknowledge support by the Saint Petersburg State University (Grant No. 94031444), SRF SKIF Boreskov Institute of Catalysis (FWUR-2024-0042) and the Russian Science Foundation (Grant No. 23-12-00016).

PY - 2025/2/13

Y1 - 2025/2/13

N2 - Chemical composition dependent vibrational modes of manganese-based bismuth telluride (MBT) magnetic topological insulators thin films grown by molecular beam epitaxy were studied by Raman spectroscopy and compared with the vibrational modes of Bi2Te3 films. Intensity of (Formula presented.) TO mode was much stronger in Bi efficient MBT film. In contrast, vibrational cross-section of (Formula presented.) LO mode was stronger in Bi deficient MBT compound. (Formula presented.) TO mode corresponds to in-plane vibrations of Bi-Te atomic layers. Deficiency of Bi atoms in the MBT indicated that the vibrational degree of freedom of Bi-Te in the septuple unit cell was less probable. Antisymmetric out-of-phase vibration of Te-Te atoms resulted in (Formula presented.) LO mode in which Bi atom was stationary, therefore vibrational cross-section of this mode for Bi deficient MBT film was stronger. A resonantly excited Eg and A1g modes was observed at excitation energy 1.57 eV associated to deformation potential and Frohlich electron–phonon coupling, respectively.

AB - Chemical composition dependent vibrational modes of manganese-based bismuth telluride (MBT) magnetic topological insulators thin films grown by molecular beam epitaxy were studied by Raman spectroscopy and compared with the vibrational modes of Bi2Te3 films. Intensity of (Formula presented.) TO mode was much stronger in Bi efficient MBT film. In contrast, vibrational cross-section of (Formula presented.) LO mode was stronger in Bi deficient MBT compound. (Formula presented.) TO mode corresponds to in-plane vibrations of Bi-Te atomic layers. Deficiency of Bi atoms in the MBT indicated that the vibrational degree of freedom of Bi-Te in the septuple unit cell was less probable. Antisymmetric out-of-phase vibration of Te-Te atoms resulted in (Formula presented.) LO mode in which Bi atom was stationary, therefore vibrational cross-section of this mode for Bi deficient MBT film was stronger. A resonantly excited Eg and A1g modes was observed at excitation energy 1.57 eV associated to deformation potential and Frohlich electron–phonon coupling, respectively.

KW - magnetic topological insulators

KW - molecular beam epitaxy

KW - polarization-resolved resonant Raman spectroscopy

KW - vibrational modes

KW - MAGNETIC TOPOLOGICAL INSULATORS

KW - MOLECULAR BEAM EPITAXY

KW - POLARIZATION-RESOLVED RESONANT RAMAN SPECTROSCOPY

KW - vibrational modes

UR - https://www.mendeley.com/catalogue/0c5ff0ff-92e5-33d5-9bc8-28a2cd87231a/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85217803127&origin=inward&txGid=f67281ea7d639135d1b7b66a7283ad6b

UR - https://elibrary.ru/item.asp?id=82488146

U2 - 10.1002/jrs.6779

DO - 10.1002/jrs.6779

M3 - Article

VL - 56

JO - Journal of Raman Spectroscopy

JF - Journal of Raman Spectroscopy

SN - 0377-0486

IS - 5

ER -