Phonon spectroscopy in a Bi2Te3 nanowire array

Bessas, Dimitrios; Töllner, William; Aabdin, Zainul; Peranio, N.; Sergueev, I.; Wille, Hans‐Christian; Eibl, O.; Nielsch, Kornelius; Hermann, Raphaël P.

doi:10.1039/c3nr02918b

Cited by 17 publications

(21 citation statements)

References 61 publications

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“…1(b)). The phonon density of states of the different Sn samples was probed by means of the nuclear resonant inelastic Xray scattering technique (also known as NIS: nuclear inelastic scattering) [37][38][39][40] . With this technique, finely monochromatized synchrotron X-rays (resolution better than 1 meV) are impinging on the sample.…”

Section: Methodsmentioning

confidence: 99%

Lattice dynamics in Sn nanoislands and cluster-assembled films

et al. 2017

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To unravel the effects of phonon confinement, the influence of size and morphology on the atomic vibrations is investigated in Sn nano islands and cluster-assembled films. Nuclear resonant inelastic X-ray scattering is used to probe the phonon density of states of the Sn nanostructures which show significant broadening of the features compared to bulk phonon behaviour. Supported by ab initio calculations, the broadening is attributed to phonon scattering and can be described within the damped harmonic oscillator model. Contrary to the expectations based on previous research, the appearance of high-energy modes above the cut-off energy is not observed. From the thermodynamic properties extracted from the phonon density of states, it was found that grain boundary Sn atoms are bound by weaker forces than bulk Sn atoms.

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Section: Methodsmentioning

confidence: 99%

Lattice dynamics in Sn nanoislands and cluster-assembled films

et al. 2017

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“…The different sites exhibit quite different phonon spectra, which leads to the observed change in the DPS for increasing iron content x, since the 6g becomes more prominent in the spectra. Additional NIS studies on the MnFe 4 Si 3 single crystal, relating the 4d and 6g modes to different crystallographic directions by utilizing the beam polarization [31,33], are provided in the supplemental material section.…”

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confidence: 99%

Elasticity and magnetocaloric effect inMnFe4Si3

et al. 2016

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The room temperature magnetocaloric material MnFe 4 Si 3 was investigated with nuclear inelastic scattering (NIS) and resonant ultrasound spectroscopy (RUS) at different temperatures and applied magnetic fields in order to assess the influence of the magnetic transition and the magnetocaloric effect on lattice dynamics. The NIS data give access to phonons with energies above 3 meV, whereas RUS probes the elasticity of the material in the MHz frequency range and thus low-energy, ∼ neV, phonon modes. A significant influence of the magnetic transition on the lattice dynamics is observed only in the low-energy, long-wavelength limit. MnFe 4 Si 3 and other compounds in the Mn 5-x Fe x Si 3 series were also investigated with vibrating sample magnetometry, resistivity measurements and Mössbauer spectroscopy in order to study the magnetic transitions and to complement the results obtained on the lattice dynamics.

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“…Thus, our experimental fi ndings demonstrate that simply scaling down a good thermoelectric material to improve the thermoelectric performance is not a straightforward approach in the case of topological insulators because of the increasing contribution from the surface states due to the increasing surface-to-volume ratio. [ 13,15,45,46,49 ] Furthermore, our approach opens new perspectives for experiments and applications based on topological insulators. [ 26 ] In fact, the topological surface states limit the power factor of (Bi 1− x Sb x ) 2 Te 3 NWs and thus achieving ZT enhancement [ 39 ] in such nanostructures becomes challenging.…”

Section: Doi: 101002/aenm201500280mentioning

confidence: 95%