Phonon anharmonicity of iron monosilicide

Povzner, A. A.; Filanovich, A. N.

doi:10.1016/j.physb.2014.09.028

Cited by 7 publications

(7 citation statements)

References 20 publications

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“…The electronic part of the heat capacity obtained in the present study is sufficiently different from that obtained using the "effective Debye modes" approximation [9,22,23] and this is crucial in the analysis of peculiarities of the strongly correlated electron subsystem. As can be seen from Fig.…”

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confidence: 79%

Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems

Povzner

Filanovich

Nogovitsyna

2017

Physica Status Solidi (b)

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Within the framework of a thermodynamic model, the phonon anharmonicity associated with both acoustic and optical vibrations of the crystal lattice is investigated. On this basis we have performed self‐consistent simulations of thermal and elastic properties of FeSi and CoSi compounds and their solid solutions Fe1–xCoxSi (x = 0.1, 0.3, 0.5), which are promising spintronic materials. The non‐lattice contributions to the heat capacity and coefficient of thermal expansion of the considered systems have been established. It is shown that the Invar effect observed in Fe0.7Co0.3Si and Fe0.5Co0.5Si is associated with anomalies of their electronic and magnetic subsystems.

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contrasting

confidence: 79%

Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems

Povzner

Filanovich

Nogovitsyna

2017

Physica Status Solidi (b)

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“…The inset to Fig. 5 shows the calculated temperature dependences of the Grüneisen parameters of CoSi and iron monosilicide [9]. As follows from these results, these parameters can be described by the expression (9) ln ( ) ln Since the Grüneisen parameter is the main characteristic of phonon anharmonicity, the anharmonicity of the lattice vibrations in CoSi is seen to depend on temperature in a complex manner and is higher than two at low temperatures, which is characteristic of systems with a rather strong phonon anharmonicity.…”

Section: Resultsmentioning

confidence: 99%

“…The self-consistent thermodynamic model is the generalization of the Debye model and was successfully used to describe the thermal and elastic properties of iron monosilicide [9] and other materials (see, e.g., [10]). Since a compound is considered in this work, we have to generalize this model.…”

Section: Description Of the Modelmentioning

confidence: 99%

Thermodynamic simulation of the elastic and thermal properties of cobalt monosilicide

2016

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A self-consistent thermodynamic model is used to calculate the temperature dependences of the heat capacity, the thermal expansion coefficient, the bulk compression modulus, the density, Debye temperature, and the Grüneisen parameter of CoSi in the temperature range 0-1400 K. The calculation results agree well with the existing experimental data and can be used to predict the properties of CoSi in the temperature range that has not been experimentally studied. Cobalt monosilicide is shown to have a significant phonon anharmonicity, which can be caused by an electron-phonon interaction, and this anharmonicity should be taken into account in the simulation of its thermoelectric properties. INTRODUCTIONCobalt monosilicide CoSi is one of the most promising materials for creating thermogenerators, which is caused by the relatively high efficiency of CoSi-based thermogenerators and the physicochemical and mechanical properties of this compound (which are appropriate for technical applications) [1-3]. Nevertheless, many important thermal and elastic properties of CoSi are poorly understood. For example, the experimental data on the CoSi density are restricted to its room-temperature value, and experimental data on the heat capacity, the elastic moduli, and the thermal expansion coefficient are known for a relatively narrow temperature range [4][5][6][7]. The authors of [7] used the density functional theory (DFT) and the Debye model to calculate the properties of CoSi as functions of temperature and pressure. Nevertheless, the results presented in [7] do not agree with the experimental data quantitatively, which can be caused by the fact that the quasi-harmonic approximation used in [7] cannot take into account the effects related to phonon anharmonicity. However, according to the neutron diffraction data in [8], the phonon spectra of iron or cobalt monosilicide are characterized by an anomalously strong anharmonicity.The purpose of this work is to develop a self-consistent thermodynamic model for CoSi to take into account the influence of phonon anharmonicity on its thermal properties. Using this model, we were able to achieve quantitative agreement with the existing experimental data and to perform a self-consistent simulation of the temperature dependences of the lattice components of the heat capacity, the bulk com-

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“…Following the same derivation as in the case of aluminum described above, we quantify the various components of the vibrational entropy, internal energy and free energy. To evaluate the expression in equation (19), we used experimental volumetric thermal expansion data from Vocadlo et al [42], and temper ature dependent compressibility values from Petrova et al [43] and Povzner et al [44]. The vibrational thermal expansion coefficient α vib was calculated by subtracting the electronic thermal expansion coefficient [45,46] from the total thermal expansion coefficient (the role of vacancies is thought to be negligible in FeSi in the temperature range considered here).…”

Section: Fesimentioning

confidence: 99%

Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements

Bansal

Aref

Dargush

et al. 2016

J. Phys.: Condens. Matter

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Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles theoretical predictions of harmonic and non-harmonic thermal behaviors using perturbation theory, ab initio molecular-dynamics, or Monte-Carlo simulations. We illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound [Formula: see text] over a wide range of temperature. Results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.

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Phonon anharmonicity of iron monosilicide

Cited by 7 publications

References 20 publications

Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems

Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems

Thermodynamic simulation of the elastic and thermal properties of cobalt monosilicide

Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements

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Phonon anharmonicity of iron monosilicide

Cited by 7 publications

References 20 publications

Numerical simulation of the lattice properties of Fe1–xCoxSi – strongly correlated electron systems

Numerical simulation of the lattice properties of Fe1–xCoxSi – strongly correlated electron systems

Thermodynamic simulation of the elastic and thermal properties of cobalt monosilicide

Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements

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Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems

Numerical simulation of the lattice properties of Fe_1–xCo_xSi – strongly correlated electron systems