Specific Heat of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>n</mml:mi></mml:math>- and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi></mml:math>-Type<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Bi</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/Mat

Shoemake, G.E.; Rayne, J.A.; Ure, R. W.

doi:10.1103/physrev.185.1046

Cited by 85 publications

(37 citation statements)

References 14 publications

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“…A non spin-polarized electronic origin of the Schottky term can not be excluded a priori. The electronic contribution in heat capacity from activated charge carriers for semiconducting Bi 2 Te 3 above 3 K is insignificant according to Shoemaker et al 53 The presence of defects provides a plausible explanation as defect formation is an important issue in Bi 2 Te 3 . The energy scale for the existence of antisite defects has been recently calculated theoretically 16 and attemps to prove their existence experimentally 54 have been carried out.…”

Section: Compoundmentioning

confidence: 99%

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B

119

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The lattice dynamics in Bi 2 Te 3 and Sb 2 Te 3 were investigated both microscopically and macroscopically using 121 Sb and 125 Te nuclear inelastic scattering, x-ray diffraction, and heat capacity measurements. In combination with earlier inelastic neutron scattering data, the element-specific density of phonon states was obtained for both compounds and phonon polarization analysis was carried out for Bi 2 Te 3 . A prominent peak in the Te specific density of phonon states at 13 meV, that involves mainly in-plane vibrations, is mostly unaffected upon substitution of Sb with Bi revealing vibrations with essentially Te character. A significant softening is observed for the density of vibrational states of Bi with respect to Sb, consistently with the mass homology relation in the long-wavelength limit. In order to explain the energy mismatch in the optical phonon region, a ∼20% force constant softening of the Sb-Te bond with respect to the Bi-Te bond is required. The reduced average speed of sound at 20 K in Bi 2 Te 3 , 1.75(1) km/s, compared to Sb 2 Te 3 , 1.85(4) km/s, is not only related to the larger mass density but also to a larger Debye level. The observed low lattice thermal conductivity at 295 K, 2.4 Wm −1 K −1 for Sb 2 Te 3 and 1.6 Wm −1 K −1 for Bi 2 Te 3 , cannot be explained by anharmonicity alone given the rather modest Grüneisen parameters, 1.7(1) for Sb 2 Te 3 and 1.5(1) for Bi 2 Te 3 , without accounting for the reduced speed of sound and more importantly the low acoustic cutoff energy.

show abstract

Section: Compoundmentioning

confidence: 99%

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B

119

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“…6 is not related to the Debye temperature, which is ∼ 182 K, beyond our temperature range. 23 The change in power law is most likely due to the competition between the magnetic and quadrupolar relaxations, where the former dominates at low temperature. Therefore, the smaller 1/T 1 at low temperature in sample #3, as compared to those in samples #1 and #2, again suggests that sample #3 has a smaller charge-carrier density than the others.…”

mentioning

confidence: 99%

Probing the bulk electronic states of Bi2Se3using nuclear magnetic resonance

Young

Lai

et al. 2012

Phys. Rev. B

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We report a nuclear magnetic resonance (NMR) study of Bi2Se3 single crystals grown by three different methods. All the crystals show 9 well-resolved peaks in their 209 Bi NMR spectra of the nuclear quadrupolar splitting, albeit with an intensity anomaly. Spectra at different crystal orientations confirm that all the peaks are purely from the nuclear quadrupolar effect, with no other hidden peaks. We identify the short nuclear transverse relaxation time (T2) effect as the main cause of the intensity anomaly. We also show that the 209 Bi signal originates exclusively from bulk, while the contribution from the topological surface states is too weak to be detected by NMR. However, the bulk electronic structure in these single crystals is not the same, as identified by the NMR frequency shift and nuclear spin-lattice relaxation rate (1/T1). The difference is caused by the different structural defect levels. We find that the frequency shift and 1/T1 are smaller in samples with fewer defects and a lower carrier concentration. Also, the low temperature power law of the temperature-dependent 1/T1 (∝ T α ) changes from the Korringa behavior α = 1 in a highly degenerate semiconductor (where the electrons obey Fermi statistics) to α < 1 in a less degenerate semiconductor (where the electrons obey Boltzmann statistics).2

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“…[7], but the spacing between the top two layers, which is the surface relaxation, was then adjusted to produce the best fit to the experimental data. The thermal vibrational amplitudes are calculated using a bulk Debye temperature of 200 K [29], while the mean square vibrational amplitudes of the top two atomic layers are enhanced isotropically by a factor of 1.6…”

mentioning

confidence: 99%

Surface structure of in situ cleaved single crystal Bi2Se3 measured by low energy ion scattering

Zhou

Zhu

Yarmoff

2016

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

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Bismuth Selenide is a two-dimensional topological insulator material composed of stacked quintuple layers (QL). The layers are held together by a weak van der Waals force that enables surface preparation by cleaving. Low energy ion scattering experiments (LEIS) show that Bi 2 Se 3 cleaved under ultra-high vacuum (UHV) has a Se-terminated structure that is consistent with cleaving between QLs. Comparison of experimental data to molecular dynamics simulations confirms the Se-termination and provides an estimate of the surface relaxation.

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Specific Heat ofn- andp-TypeBi2
G.E. Shoemake
¹
,
J.A. Rayne
²
,
R. W. Ure
³

Cited by 85 publications

References 14 publications

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B

Probing the bulk electronic states of Bi2Se3using nuclear magnetic resonance

Surface structure of in situ cleaved single crystal Bi2Se3 measured by low energy ion scattering

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Specific Heat ofn- andp-TypeBi2G.E. Shoemake1, J.A. Rayne2, R. W. Ure3

Cited by 85 publications

References 14 publications

Lattice dynamics in Bi2Te3and Sb2TeBessas1, Sergueev2, Wille3 et al. 2012Phys. Rev. B

Lattice dynamics in Bi2Te3and Sb2TeBessas1, Sergueev2, Wille3 et al. 2012Phys. Rev. B

Probing the bulk electronic states of Bi2Se3using nuclear magnetic resonance

Surface structure of in situ cleaved single crystal Bi2Se3 measured by low energy ion scattering

Contact Info

Product

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About

Specific Heat ofn- andp-TypeBi2
G.E. Shoemake
¹
,
J.A. Rayne
²
,
R. W. Ure
³

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B

Lattice dynamics in Bi2Te3and Sb2Te
Bessas
¹
,
Sergueev
²
,
Wille
³

et al. 2012
Phys. Rev. B