Unification of the phonon mode behavior in semiconductor alloys: Theory and<i>ab initio</i>calculations

Pagès, O.; Postnikov, A. V.; Kassem, M.; Chafi, A.; Nassour, Ayoub; Doyen, S.

doi:10.1103/physrevb.77.125208

Cited by 40 publications

(49 citation statements)

References 36 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, some Raman active modes predicted for the rhombohedral symmetry are not observed in the Mn-doped 0.67BiFeO 3 -0.33BaTiO 3 multiferroic ceramics, which is due to the too small rhombohedral distortions to activate these Raman modes, or namely the symmetry-forbidden scattering. [19]. Similar phenomenon was reported in the La-doped BiFeO 3 -PbTiO 3 mixed crystal system [20].…”

Section: Methodssupporting

confidence: 66%

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Hang¹,

Zhou²,

Zhu³

et al. 2013

J Adv Ceram

View full text Add to dashboard Cite

0.67BiFeO 3 -0.33BaTiO 3 multiferroic ceramics doped with x mol% MnO 2 (x = 2-10) were synthesized by solid-state reaction. The formation of a perovskite phase with rhombohedral symmetry was confirmed by X-ray diffraction (XRD). The average grain sizes were reduced from 0.80 m to 0.50 m as increasing the Mn-doped levels. Single crystalline nature of the grains was revealed by high-resolution transmission electron microscopy (HRTEM) images and electron diffraction patterns. Polar nano-sized ferroelectric domains with an average size of 9 nm randomly distributed in the ceramic samples were revealed by TEM images. Ferroelectric domain lamellae (71° ferroelectric domains) with an average width of 5 nm were also observed. Vibrational modes were examined by Raman spectra, where only four Raman peaks at 272 cm 1 (E-4 mode), 496 cm 1 (A 1 -4 mode), 639 cm 1 , and 1338 cm 1 were observed. The blue shifts in the E-4 and A 1 -4 Raman mode frequencies were interpreted by a spring oscillator model. The dieletric constants of the present ceramics as a function of the Mn-doped levels exhibited a V-typed curve. They were in the range of 350-700 measured at 10 3 Hz, and the corresponding dielectric losses were in range of 0.43-0.96, approaching to 0.09 at 10 6 Hz.

show abstract

Section: Methodssupporting

confidence: 66%

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Hang¹,

Zhou²,

Zhu³

et al. 2013

J Adv Ceram

View full text Add to dashboard Cite

show abstract

“…In the framework of this model, the optical phonons in AB 1-x C x alloys are classified in three main types: (i) 1-bond→1-mode, where each phonon is associated with two branches related to the A-B and A-C bonds respectively, (ii) 2-bond→1-mode, where each phonon is associated with one branch of mixed (A-B,A-C) character, and (iii) modified-2-mode, where each phonon is associated with two branches of mixed character. Further details can be found in reference [2]. Representative systems for these classes are respectively In 1-x Ga x As, ZnTe 1-x Se x and In 1-x Ga x P.…”

mentioning

confidence: 99%

“…In the discussion, we focus on TO modes (open symbols), as usual. The more complex LO modes (plain symbols) are discussed elsewhere [2].…”

mentioning

confidence: 99%

“…Our view is that the MREI model misses the essence of the phonon behavior in SC alloys, and that due to the local character of the bond properties, proper understanding of TO phonons in alloys requires a details insight into the topologies of the substituting species. We proposed a new phenomenological model which falls into the scope of the percolation site theory [2]. In this view, AB 1-x C x alloys are considered as composite systems made of two AB-like and AC-like regions resulting from natural fluctuations in the alloy composition at the local scale, see Fig.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Description of vibrational properties of random alloy ZnTe_1–xSe_x within the percolation model

Souhabi¹,

Chafi²,

Kassem³

et al. 2009

Phys. Status Solidi (c)

Self Cite

View full text Add to dashboard Cite

We discuss the classification of the phonon type behavior of semiconductor alloys as apparent in the Raman and infrared spectra, i.e. in terms of types (i) 1‐bond→1‐mode and (ii) 2‐bond→1‐mode (both covered by the Modified Random Element Isodisplacement model, operating at the macroscopic scale), and also (iii) the modified 2‐mode type (exceptional), in the framework of the recent 1‐bond→2‐mode percolation model based on a description of the alloy disorder at the mesoscopic scale. The leading systems of types (i) and (iii), i.e., InGaAs and InGaP, respectively, were earlier shown to obey the percolation model. The aim of this work is to investigate whether the percolation model further extends to the leading system of the last type (ii), i.e. ZnTeSe. With this end in view, we perform a careful re‐examination of the Raman and infrared spectra of this alloy, as available in the literature. Special attention is awarded to the discussion and modeling of the puzzling multi‐mode infrared reflectivity spectra. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

“…4 of Ref. 1. Below we discuss the ab initio predictions of the single impurity vs. impurity pair -related phonon behaviour for (Ga,In)As and (Ga,In)P alloys.…”

mentioning

confidence: 99%

Impurity Modes and Effect of Clustering in Diluted Semiconductor Alloys

Postnikov¹,

Pagès²,

Nassour³

et al. 2007

3rd France-Russia Seminar

Self Cite

View full text Add to dashboard Cite

The variation of TO zone-center vibration spectra with concentration in mixed zincblende-type semiconductors can be understood within a paradigm of uni ed "one bond -two modes" approach, which has been recently outlined as a rather general concept, 1 and emerges from a number of previous experimental and theoretical studies. 2,3 The crucial issue is that the vibration frequency, associated with a certain cation-anion bond, depends on the length of the latter, and the bond length, in its turn, depends not only on the average alloy concentration, but on local variations of it. In an (A,B)C substitutional alloy, the A-C bond length differ in A-rich and A-poor regions, yielding a splitting of the A-C vibration frequency. Such splittings can be measured and reproduced in rst-principles calculations.An analysis of vibration spectra helps to get an insight into the structural short-range (clustering) and long-range (formation of extended chains of certain cation-anion pairs and other structural motives at the mesoscopic scale) tendencies. For this however, one needs rstprinciples benchmark calculations for representative model systems (see, e.g., Ref. 4 for the ZnSe-BeSe alloys). The simplest yet important result from rst-principles calculations is a prediction of how the impurity phonon mode evolves as isolated (distant) impurities get clustered.In the present contribution, we outline the results of rst-principles calculations of phonon frequencies and vibration patterns, in the dilution limits of several mixed semiconductor alloys, Be x Zn 1−x Se, Ga x In 1−x As and Ga x In 1−x P. The calculations have been done by the SIESTA method 5 for cubic 64-atom supercells, with one or two cation atoms substituted by impurity species, that corresponds to impurity contents of 3% and 6%, respectively. The initial unconstrained structure relaxation for each supercell chosen was followed by a calculation of phonons by nite displacement technique. Each of the atoms in the supercell were subject to 6 consecutive small cartesian displacements, and the forces induced on all atoms in the supercell resulted in corresponding force constants.The analysis of results is the simplest for Be x Zn 1−x Se, a system with large contrast in masses and elastic properties between its parent compounds, that leads to a big separation between Zn-related and Be-related phonon modes (see Ref. 4 for details). Fig. 1 shows the phonon Fig. 1. Phonon density of states of Be, after rst-principles calculations for Be n Zn 32−n Se 32 supercells, with 1,..4 Be cations neighbouring the same Se anion. The supercell for n=4 is shown in the inset.

show abstract

Unification of the phonon mode behavior in semiconductor alloys: Theory andab initiocalculations

Cited by 40 publications

References 36 publications

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Description of vibrational properties of random alloy ZnTe_1–xSe_x within the percolation model

Impurity Modes and Effect of Clustering in Diluted Semiconductor Alloys

Contact Info

Product

Resources

About

Unification of the phonon mode behavior in semiconductor alloys: Theory andab initiocalculations

Cited by 40 publications

References 36 publications

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Structural, spectroscopic, and dielectric characterizations of Mn-doped 0.67BiFeO3-0.33BaTiO3 multiferroic ceramics

Description of vibrational properties of random alloy ZnTe1–xSex within the percolation model

Impurity Modes and Effect of Clustering in Diluted Semiconductor Alloys

Contact Info

Product

Resources

About

Description of vibrational properties of random alloy ZnTe_1–xSe_x within the percolation model