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In this paper we report phonon dynamics in chemically synthesized Zn1- xMgxO (0\leqx\leq0.07) and Zn1-yCdyO (0\leqy\leq0.03) alloy nanostructures of sizes ~10 nm using non-resonant Raman and Fourier Transformed Infrared Spectroscopy (FTIR).…

Materials Science · Physics 2011-09-13 Manoranjan Ghosh , Nita Dilawar , A. K. Bandyopadhyay , A. K. Raychaudhuri

The observation of the local - mode vibration, the two - mode behavior of the LO phonons at large isotope concentration, as well as large line broadening in LIH - D mixed crystals directly evidence strong additional phonon scattering due to…

Materials Science · Physics 2015-05-13 V. G. Plekhanov

Phonon modes found in low frequency Raman scattering from $CdS_{1-x}Se_x$ nanocrystals embedded in borosilicate glass arising from confined acoustic phonons are investigated. In addition to the breathing modes and quadrupolar modes, two…

Materials Science · Physics 2008-03-10 Sanjeev K. Gupta , Satyaprakash Sahoo , Prafulla K. Jha , A. K. Arora , Y. M. Azhniuk

We report synthesis of Cd substituted ZnO nanostructures (Zn1-xCdxO with x upto \approx .09) by high pressure solution growth method. The synthesized nanostructures comprise of nanocrystals that are both particles (~ 10-15 nm) and rods…

Materials Science · Physics 2011-09-13 Manoranjan Ghosh , A. K. Raychaudhuri

A modified phonon confinement model considering the size distribution, an improved phonon dispersion curve and a confinement function is developed for the calculation of size dependent Raman spectra of the silicon (Si) nanocrystals. The…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Sanjeev K. Gupta , Prafulla K. Jha

We derive within the dielectric-continuum model an integral equation that defines interface and confined polar optical-phonon modes in nanocrystals with wurtzite crystal structure. It is demonstrated theoretically, that while the frequency…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Vladimir A. Fonoberov , Alexander A. Balandin

The Cd1-xZnxTe semiconductor alloy is a regular system regarding its macroscopic mechanic properties in that its experimental bulk modulus exhibits a linear x-dependence, in line with ab initio predictions. Complexity arises at the bond…

Disorder-induced broadening of optical vibrational eigenmodes in nanoparticles of nonpolar crystals is studied numerically. The methods previously used to treat phonons in defectless particles are adjusted for numerical evaluation of the…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 Sergei V. Koniakhin , Oleg I. Utesov , Andrey G. Yashenkin

We investigate the acoustic normal modes ("phonons") of a 1D microfluidic droplet crystal at the crossover between 2D flow and confined 1D plug flow. The unusual phonon spectra of the crystal, which arise from long-range hydrodynamic…

Fluid Dynamics · Physics 2010-08-10 Tsevi Beatus , Roy Bar-Ziv , Tsvi Tlusty

We calculate low-frequency Raman scattering from the confined acoustic phonon modes of CdS1-xSex nanoparticles embedded in borosilicate glass. The calculation of the Raman scattering by acoustic phonons in nanoparticles has been performed…

Mesoscale and Nanoscale Physics · Physics 2009-04-16 Sanjeev K. Gupta , Prafulla K. Jha , Satyaprakash Sahoo , A. K. Arora , Y. M. Azhniuk

Confined acoustic and optical phonons in Si nanoclusters embedded in sapphire, synthesized using ion-beam implantation are investigated using Raman spectroscopy. The l = 0 and l = 2 confined acoustic phonons, found at low Raman shift, are…

Materials Science · Physics 2008-09-10 Satyaprakash Sahoo , S. Dhara , S. Mahadevan , A. K. Arora

Microscopic description of Raman spectra in nanopowders of nonpolar crystals is accomplished by developing the theory of disorder-induced broadening of optical vibrational eigenmodes. Analytical treatment of this problem is performed, and…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 Oleg I. Utesov , Andrey G. Yashenkin , Sergei V. Koniakhin

Optical properties of the lead halide perovskites nanocrystals are controlled by confined excitons and rich spectrum of confined acoustic and optical phonons. We study experimentally and theoretically the exciton-phonon interaction in…

Longitudinal-optical (LO) mode phonon branches of KCl and NaCl were measured using inelastic X-ray scattering (IXS) at 300 K and calculated by the first-principles phonon calculation with the stochastic self-consistent harmonic…

Materials Science · Physics 2022-07-13 Atsushi Togo , Hiroyuki Hayashi , Terumasa Tadano , Satoshi Tsutsui , Isao Tanaka

The evolution of the optical phonons in layered semiconductor alloys SnSe1-xSx is studied as a function of the composition by using polarized Raman spectroscopy with six different excitation wavelengths (784.8, 632.8, 532, 514.5, 488, and…

Optical and vibrational properties of bare and CdS shelled CdSe nanocrystalline particles are investigated. To confirm the formation of such nanocrystals in our samples we estimate their average particle sizes and size distributions using…

Materials Science · Physics 2009-11-10 A. Singha , B. Satpati , P. V. Satyam , Anushree Roy

Exciton-phonon coupling limits the homogeneous emission linewidth of nanocrystals. Hence, a full understanding of it is crucial. In this work, we statistically investigate exciton-phonon coupling by performing single-particle spectroscopy…

In the present paper, we utilize the coupled-oscillator model describing the hybridization of optical phonons in touching and/or overlapping particles in order to study the Raman spectra of nanoparticles organized into various types of…

Mesoscale and Nanoscale Physics · Physics 2023-12-01 S. V. Koniakhin , O. I. Utesov , A. G. Yashenkin

UV Raman scattering studies show longitudinal optical (LO) mode up to 4th order in wurtzite GaN nanowire system. Frohlich interaction of electron with the long range electrostatic field of ionic bonded GaN gives rise to enhancement in LO…

The interaction between excitons and phonons in semiconductor nanocrystals plays a crucial role in the exciton energy spectrum and dynamics, and thus in their optical properties. We investigate the exciton2 phonon coupling in giant-shell…

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