Phonon spectrum and thermal properties of cubic Si3N4 from first-principles calculations

Fang, Chung; Wijs, de Ga; Hintzen, Htjm Bert

doi:10.1063/1.1566473

Cited by 55 publications

(38 citation statements)

References 42 publications

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“…Overall, our calculation is in better agreement with the experimental data of Paszkowicz et al 40 , and the the- oretical data of Fang et al 41 The calculation reported by Paszkowicz et al, which is based a simplified Debye model to approximate the phonon density of states, 40 is consistent with our data at temperatures below 500 K. However, their predicted TEC at high temperatures is apparently lower than all other three calculations that are based on the first-principles phonon density of states. At low temperatures, the prediction of γ-Si 3 N 4 from Kuwabara et al is noticeably larger than other calculations, including ours.…”

Section: -36supporting

confidence: 81%

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Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Dong

McMillan

et al. 2011

Phys. Rev. B

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We have combined first-principles calculations and high pressure experiments to study pressure induced phase transitions in silicon nitride (Si3N4). Within the quasi-harmonic approximation, we predict that the α phase is always metastable relative to the β phase over the wide pressuretemperature range. Our lattice vibration calculations indicate that there are two significant and competing phonon-softening mechanisms in the β-Si3N4, while phonon softening in the α-Si3N4 is rather moderate.When the previously observed equilibrium high-pressure and high-temperature β→γ transition is by-passed at room temperatures (RT) due to kinetic reasons, the β phase is predicted to undergo a first-order structural transformation to a denser P6 phase above 39 GPa. The estimated enthalpy barrier height is less than 70 meV/atom, which suggests that the transition is kinetically possible around room temperatures. This predicted new high-pressure metastable phase should be classified as a "post-phenacite" phase. Our high-pressure X-ray diffraction experiment confirm this predicted room-temperature phase transition around 34 GPa. No similar RT phase transition is predicted for α-Si3N4. Furthermore, we discuss the differences in pressure dependencies of phonon modes in the α, β and γ phases and the consequences on their thermal properties. We attribute the phonon modes with negative Grüneisen ratios in the α and β phases as the cause of the predicted negative thermal expansion coefficients (TEC) at low temperatures in these two phases, and predict no negative TEC in the γ phase.

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Section: -36supporting

confidence: 81%

“…Our zero-pressure results are compared with available experimental data [33][34][35][36][37][38][39][40] and previous calculations. 21,22,41,42 Conclusions are drawn in Sec. IV.…”

mentioning

confidence: 99%

Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Dong

McMillan

et al. 2011

Phys. Rev. B

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“…It has a hardness comparable to the hardest known oxide (stishovite, a high-pressure phase of SiO 2 ) [2][3][4][5][6] and significantly greater than the hardness of α-and β-Si 3 N 4 [7]. In recent years, many experiments on the properties of Si 3 N 4 have been performed, and their theories have been studied [8][9][10][11][12][13][14][15][16][17][18]. Among all the properties of Si 3 N 4 studied so far, the thermodynamic properties have been an intriguing subject.…”

Section: Introductionmentioning

confidence: 99%

Analytic Equation of State and Thermodynamic Properties for α-, β-, and γ-Si₃N₄Based on Analytic Mean Field Approach

et al. 2008

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The analytic mean field potential approach is applied to α-, β-, and γ-Si 3 N 4 . The analytic expressions for the Helmholtz free energy, internal energy, and equation of state were derived. The formalism for the case of the Morse potential is used in this work. Its six potential parameters are determined through fitting the compression experimental data of α-, β-, and γ-Si 3 N 4 . The calculated compression curves of α-, β-, and γ-Si 3 N 4 are in good agreement with the available experimental data. This suggests that the analytic mean field potential approach is a very useful approach to study the thermodynamic properties of Si 3 N 4 . Furthermore, we predict the variation of the free energy and internal energy with the molar volume at several higher temperatures and calculate the temperature dependence of the molar volume, bulk modulus, thermal expansion coefficient and isochoric heat capacity at zero pressure.

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“…Recently, ab initio calculations have been performed to calculate infrared and Raman phonon modes at the zone centre by Pascal and Gervais [14] and Wijs et al [15] for MgAl 2 O 4 and by Fang et al [16] for cubic Si 3 N 4 . Very recently, the ab initio technique has been used to calculate the lattice dynamical properties of LiMn 2 O 4 by Fang et al [17].…”

Section: Introductionmentioning

confidence: 99%

Lattice Dynamical Calculations for Inverse Spinel Compounds

Kushwaha

2015

Acta Phys. Pol. A

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Lattice dynamical calculations have been performed for inverse spinel structure compounds MIn2S4 (M = Mn and Co) using the proposed six parameter bond-bending force constant model. In this model, the short-range force constant is calculated by using the Taylor expansion of the potential energy in the harmonic approximation. This model is applied to study the zone-centre (Γ = 0) phonon frequencies of inverse spinels MIn2S4 (M = Mn and Co). The signicant outcome of the present work is that the second neighbor interactions (octahedral bonding) are stronger than the rst neighbor interactions (tetrahedral bonding). The zone-center phonon frequencies, calculated using these parameters, are found to be in very good agreement with the observed results.

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Phonon spectrum and thermal properties of cubic Si3N4 from first-principles calculations

Cited by 55 publications

References 42 publications

Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Analytic Equation of State and Thermodynamic Properties for α-, β-, and γ-Si₃N₄Based on Analytic Mean Field Approach

Lattice Dynamical Calculations for Inverse Spinel Compounds

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Phonon spectrum and thermal properties of cubic Si3N4 from first-principles calculations

Cited by 55 publications

References 42 publications

Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Equilibrium and metastable phase transitions in silicon nitride at high pressure: A first-principles and experimental study

Analytic Equation of State and Thermodynamic Properties for α-, β-, and γ-Si3N4Based on Analytic Mean Field Approach

Lattice Dynamical Calculations for Inverse Spinel Compounds

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Analytic Equation of State and Thermodynamic Properties for α-, β-, and γ-Si₃N₄Based on Analytic Mean Field Approach