Origin of the Boson Peak in Systems with Lattice Disorder

Taraskin, S. N.; Loh, Yen Lee; Natarajan, Ganapati; Elliott, S. R.

doi:10.1103/physrevlett.86.1255

Cited by 299 publications

(365 citation statements)

References 19 publications

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“…This peak is located at an almost constant energy, in an energy region typical of the boson peak (BP), as it will be also shown from the more detailed analysis. The comparison with experimental results on other systems and with moleculardynamics simulations 7,8,23 suggests the interpretation of this low-frequency feature as the high-frequency evolution of the transverse-acoustic mode. 25 However, it should be noted that the density fluctuation modes loose their symmetry as the wave vector is increased, so that the longitudinal and transverse terms have not a well defined significance.…”

Section: Methodsmentioning

confidence: 83%

Neutron scattering investigation of high-frequency dynamics in glassy glucose

et al. 2012

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The vibrational dynamics of vitreous glucose has been investigated by means of inelastic neutron scattering experiments, exploiting the coherent scattering cross section of deuterium in a fully deuterated sample and the high incoherent scattering cross section of hydrogen in a hydrogenated sample. The first part of the experiment allowed a rather detailed investigation of the collective dynamics in the THz range. The second part of the experiment was used to derive some information on the vibrational density of states of the system. The experiment confirms the presence of a propagating vibrational mode which is the natural extension at THz frequencies of the lower frequencies longitudinal sound mode. In addition, a second mode is also observed at a lower and almost constant frequency, showing an increasing intensity on reducing the wavelength. By comparing the dispersion relations of these collective modes to the experimental density of states, a possible relation between the low frequency mode and the well known excess of low frequency modes, that is, the boson peak, is identified.

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Section: Methodsmentioning

confidence: 83%

Neutron scattering investigation of high-frequency dynamics in glassy glucose

et al. 2012

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“…[13][14][15][16] Figure 8 presents the reduced low-frequency Raman spectra of KMWPO and RbMWPO glasses in two different reduction schemes:…”

Section: E Low-frequency Raman Scattering: Boson Peakmentioning

confidence: 99%

“…The first technique gives information about short-range structure of glasses and allows studying the so-called "Boson peak." [12][13][14][15][16] Study of the Boson peak is of great interest since its origin still remains unclear. [13][14][15][16] On the other hand, heat capacity studies may provide, among others, some information on fragility, structural relaxation, and aging effects in glasses.…”

Section: Introductionmentioning

confidence: 99%

“…[12][13][14][15][16] Study of the Boson peak is of great interest since its origin still remains unclear. [13][14][15][16] On the other hand, heat capacity studies may provide, among others, some information on fragility, structural relaxation, and aging effects in glasses. [17][18][19][20] A particularly suitable technique for studies of glass transitions is modulated differential scanning calorimetry ͑MDSC͒ since it gives information on both real and imaginary parts of heat capacity.…”

Section: Introductionmentioning

confidence: 99%

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Heat capacity, Raman, and Brillouin scattering studies of M2O–MgO–WO3–P2O5 glasses (M=K,Rb)

Mączka

Hanuza

Baran

et al. 2006

The Journal of Chemical Physics

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The authors report the results of temperature-dependent Brillouin scattering from both transverse and longitudinal acoustic waves, heat capacity studies as well as room temperature Raman scattering studies on M 2 O-MgO-WO 3 -P 2 O 5 glasses ͑M=K,Rb͒. These results were used to obtain information about structure and various properties of the studied glasses such as fragility, elastic moduli, ratio of photoelastic constants, and elastic anharmonicity. They have found that both glasses have similar properties but replacement of K + ions by Rb + ions in the glass network leads to decrease of elastic parameters and P 44 photoelastic constant due to increase of fragility. Based on Brillouin spectroscopy they show that a linear correlation between longitudinal and shear elastic moduli holds over a large temperature range. This result supports the literature data that the Cauchy-type relation represents a general rule for amorphous solids. An analysis of the Boson peak revealed that the form of the frequency distribution of the excess density of states is in agreement with the Euclidean random matrix theory. The reason of the observed shift of the maximum frequency of the Boson peak when K + ions are substituted for Rb + ions is also briefly discussed.

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“…Recent work on harmonic lattice models demonstrated that softening of disordered force constants can smear and push to low frequencies peaks which exist in the crystalline DOS [10,11,12]. In another approach the vibrations of a random distribution of atoms, interacting with a Gaussian-shaped pair potential, was studied [13] in a harmonic scalar approximation.…”

Section: Introductionmentioning

confidence: 99%

Vibrations and relaxations in a soft sphere glass: boson peak and structure factors

Schober

2004

J. Phys.: Condens. Matter

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The dynamics of a soft sphere model glass, studied by molecular dynamics, is investigated.The vibrational density of states divided by ω 2 shows a pronounced boson peak. Its shape is in agreement with the universal form derived for soft oscillators interacting with sound waves. The excess vibrations forming the boson peak have mainly transverse character. From the dynamic structure factor in the Brillouin regime pseudo dispersion curves are calculated. Whereas the longitudinal phonons are well defined up to the pseudo zone boundary the transverse ones rapidly get over-damped and go through the Ioffe-Regel limit near the boson peak frequency. In the high q regime constant-ω scans of the dynamic structure factor for frequencies around the boson peak are clearly distinct from those for zone boundary frequencies. Above the Brillouin regime, the scans for the low frequency modes follow closely the static structure factor. This still holds after a deconvolution of the exact harmonic eigenmodes into local and extended modes. Also the structure factor for local relaxations at finite temperatures resembles the static one. This semblance between the structure factors mirrors the collective motion of chain like structures in both low frequency vibrations and atomic hopping processes, observed in the earlier investigations.

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Origin of the Boson Peak in Systems with Lattice Disorder

Cited by 299 publications

References 19 publications

Neutron scattering investigation of high-frequency dynamics in glassy glucose

Neutron scattering investigation of high-frequency dynamics in glassy glucose

Heat capacity, Raman, and Brillouin scattering studies of M2O–MgO–WO3–P2O5 glasses (M=K,Rb)

Vibrations and relaxations in a soft sphere glass: boson peak and structure factors

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