Non-Debye excess heat capacity and boson peak of binary lithium borate glasses

Matsuda, Yu; Kawaji, Hitoshi; Ataké, Tooru; Yamamura, Yuichi; Yasuzuka, Shuma; Saito, Kazuya; Kojima, Seiji

doi:10.1016/j.jnoncrysol.2010.06.066

Cited by 7 publications

(2 citation statements)

References 25 publications

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“…Dissatisfaction with the Debye theory brought up attempts to improve its agreement with experiment by introducing more parameters to fit the empirical equations to the observation data. Sometimes large discrepancies between the Debye theory and experiments are assigned to peculiar properties of a specific state of matter, such as glass [58]. However, the shape of the low-temperature graphs in Ref.…”

Section: Discussionmentioning

confidence: 99%

The field theory of specific heat

Gusev

2016

Russ. J. Math. Phys.

121

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Finite temperature quantum field theory in the heat kernel method is used to study the heat capacity of condensed matter. The lattice heat is treated a la P. Debye as energy of the elastic (sound) waves. The dimensionless functional of free energy is re-derived with a cut-off parameter and used to obtain the specific heat of crystal lattices. The new dimensionless thermodynamical variable is formed as the Planck's inverse temperature divided by the lattice constant. The dimensionless constant, universal for a class of crystal lattices, which determines the low temperature region of molar specific heat, is introduced and tested with the data for diamond lattice crystals.The low temperature asymptotics of specific heat is found to be the fourth power in temperature instead of the cubic power law of the Debye theory. Experimental data for the carbon group elements (silicon, germanium) and other materials decisively confirm the quartic law. The true low temperature regime of specific heat is defined by the surface heat, therefore, it depends on geometrical characteristics of a body, while the absolute zero temperature limit is geometrically forbidden. The limit on a growth of specific heat at temperatures close to critical points, known as the Dulong-Petit law, appears from the lattice constant cut-off. Its value depends on the lattice type and it is the same for materials with the same crystal lattice. The Dulong-Petit values of compounds are equal to those of elements with the same crystal lattice type, if one mole of solid state matter were taken as the Avogadro number of the lattice atoms. This means the Neumann-Kopp rule is valid only in some cases.

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Section: Discussionmentioning

confidence: 99%

The field theory of specific heat

Gusev

2016

Russ. J. Math. Phys.

121

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“…borate glasses. 39,40 Not only does the width and intensity of the peak vary in opposite ways over such a wide range, but the contributions to the calorimetric and vibrational anomalies of other kinds of excitations such as low-frequency optic modes, which would be specific to each glass, remains small enough not to introduce significant noise into the universal representation. This conclusion agrees with the fact that the deviations of the data from the master curve of Fig.…”

Section: E Universality Of the Boson Peakmentioning

confidence: 99%

Boson peak of alkali and alkaline earth silicate glasses: Influence of the nature and size of the network-modifying cation

Richet

2012

The Journal of Chemical Physics

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The influence of the size of the alkaline earth cation on the boson peak of binary metasilicate glasses, MSiO(3) (M = Mg, Ca, Sr, Ba), has been investigated from vibrational densities of states determined by inversion of low-temperature heat capacities. As given both by C(p)/T(3) and g(ω)/ω(2), the intensity of the boson peak undergoes a 7-fold increase from Mg to Ba, whereas its temperature and frequency correlatively decrease from 18 to 10 K and from 100 to 20 cm(-1), respectively. The boson peak results from a combination of librations of SiO(4) tetrahedra and localized vibrations of network-modifying cations with non-bridging oxygens whose contribution increases markedly with the ionic radius of the alkaline earth. As a function of ionic radii, the intensity for Sr and Ba varies in the same way as previously found for alkali metasilicate glasses. The localized vibrations involving alkali and heavy alkaline earth cations appear to be insensitive to the overall glass structure. Although the new data are coherent with an almost linear relationship between the temperature of the boson peak and transverse sound velocity, pure SiO(2) and SiO(2)-rich glasses make marked exceptions to this trend because of the weak transverse character of SiO(4) librations. Finally, the universality of the calorimetric boson peak is again borne out because all data for silicate glasses collapse on the same master curve when plotted in a reduced form (C(P)∕/T(3))/(C(P)/T(3))(b) vs. T/T(b).

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Low-temperature heat capacity of alkali metal borate glass

Kojima

Kawaji

2018

J Therm Anal Calorim

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Non-Debye excess heat capacity and boson peak of binary lithium borate glasses

Cited by 7 publications

References 25 publications

The field theory of specific heat

The field theory of specific heat

Boson peak of alkali and alkaline earth silicate glasses: Influence of the nature and size of the network-modifying cation

Low-temperature heat capacity of alkali metal borate glass

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