Near Kohn anomalies in the phonon dispersion relations of lead chalcogenides

Kilián, Ondřej; Allan, G.; Wirtz, Ludger

doi:10.1103/physrevb.80.245208

Cited by 39 publications

(26 citation statements)

References 34 publications

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“…The investigation of third-and higher-order elastic constants therefore deserves more thorough treatment. For the phonons of lead chalcogenides, a parameterization within the shell-model [25,26] or recent ab initio calculations [27][28][29] yields a reasonable agreement with experimental phonon dispersions. Results depend on the parameters for the interaction potentials because the vibrational contribution to the elastic constant contains a sum over all phonons.…”

Section: Resultsmentioning

confidence: 83%

Temperature Dependent Anharmonic Properties of Lead Chalcogenides

Raju

2010

Acta Phys. Pol. A

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Calculations were made to investigate the anharmonic properties of lead chalcogenides PbS, PbSe and PbTe at elevated temperatures by means of primary physical parameters viz. nearest-neighbour distance and hardness parameter using long-and short-range potentials. Higher-order elastic constants are computed up to their melting temperature for these crystals. The first order pressure derivatives of second-and third-order elastic constants, the second-order pressure derivatives of second-order elastic constants and partial contractions are also evaluated at different temperatures. As the experimental elastic constants are not available at high temperatures, hence our results were only compared with the available values obtained at room temperature. The nature of the elastic behaviour in these compounds was analyzed.

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Section: Resultsmentioning

confidence: 83%

Temperature Dependent Anharmonic Properties of Lead Chalcogenides

Raju

2010

Acta Phys. Pol. A

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“…As found in previous studies, the TO mode at the Gamma point is soft and directly relates to the ferroelectric ground state [58,59]. The ferroelectric mode is difficult to calculate accurately due to its strong tempearture and volume dependences, and different pseudopotentials and lattice constants lead to different frequencies [58][59][60].…”

Section: A Comparison With Experimental Resultsmentioning

confidence: 95%

Phonon conduction in PbSe, PbTe, and PbTe1−xSexfrom first-principles calculations

et al. 2012

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We apply first-principles calculations to lead selenide (PbSe) and lead telluride (PbTe) and their alloys (PbTe 1-x Se x ) which are potentially good thermoelectric materials, to investigate their phonon transport properties. By accurately reproducing the lattice thermal conductivity, we validate the approaches adopted in this work. We then compare and contrast PbSe and PbTe, evaluate the importance of the optical phonons to lattice thermal conductivity, and estimate the impacts of nanostructuring and alloying on further reducing the lattice thermal conductivity. The results indicate that: 1) the optical phonons are important not only because they directly comprise over 20% of the lattice thermal conductivity, but also because they provide strong scattering channels for acoustic phonons, which is crucial for the low thermal conductivity; 2) nanostructures of less than ~10 nm are needed to reduce the lattice thermal conductivity for pure PbSe and PbTe; 3) alloying should be a relatively effective way to reduce the lattice thermal conductivity.

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“…The lead chalcogenides PbX (X = S, Se, or Te) are unusual IV-VI semiconductors with a rock salt crystal structure and with very small direct band gaps (410-280 meV at room temperature 1 ) at the high-symmetry point L. This band gap can be reduced to zero upon compressing the lattice, 2,3 and in its calculation, the effects of both spin-orbit coupling and electron correlation must be carefully taken into account. 3,4 Closely related to the electronic band structure, the lattice dynamics of PbX (Ref.…”

Section: Introductionmentioning

confidence: 99%

Anomalous quantum confinement of the longitudinal optical phonon mode in PbSe quantum dots

et al. 2013

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We have investigated the diameter dependence of the Raman spectra of lead selenide nanocrystals. The first-order Raman peak at about 136 cm −1 and its second-order overtone at twice this wavenumber move up in energy with decreasing nanocrystal diameter. This anomalous behavior is interpreted in terms of quantum confinement of the longitudinal optical (LO) phonon whose frequency displays a minimum at in the dispersion of bulk PbSe. We perform ab initio calculations of the phonons of PbSe slabs with up to 15 layers. The LO mode perpendicular to the slab shifts indeed upwards with decreasing layer thickness, thus validating the interpretation of the anomalous radius dependence of the Raman spectra in terms of quantum confinement.

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Near Kohn anomalies in the phonon dispersion relations of lead chalcogenides

Cited by 39 publications

References 34 publications

Temperature Dependent Anharmonic Properties of Lead Chalcogenides

Temperature Dependent Anharmonic Properties of Lead Chalcogenides

Phonon conduction in PbSe, PbTe, and PbTe1−xSexfrom first-principles calculations

Anomalous quantum confinement of the longitudinal optical phonon mode in PbSe quantum dots

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