Modeling of anomalous thermodynamic properties using lattice dynamics and inelastic neutron scattering

Spin-phonon coupling, high-pressure phase transitions, and thermal expansion of multiferroicGaFeO3: A combined first principles and inelastic neutron scattering study

“…The calculation of the thermal expansion of GaFeO 3 is carried out within the quasi-harmonic approximation (QHA). In QHA, each phonon mode contributes to the volume thermal expansion coefficient [53,54], given by: transition (up to 1368 K) [28]. The comparison between the experimental and calculated thermal expansion character is presented in Figure 9(b).…”

Thermodynamic Properties of Solids: Experiment and Modeling

“…The macroscopic thermodynamic properties [1][2][3][4][5][6][7][8][9][10][11] are determined by microscopic crystalline and electronic structure and atomic vibrations, and these are determined by the nature of bonding between the atoms. In this book, we focus on the understanding and modeling of these microscopic and macroscopic properties and the experimental techniques [12][13][14][15][16][17][18][19][20][21] used in their investigation.The modeling of the structure, dynamics, and various thermodynamic properties is done either by the first-principles quantum mechanical methods [6,7] or by the semiempirical methods [8][9][10][11] largely based on models of interatomic interactions. The former is computationally far more intensive; therefore, its application to complex structures has been more recent and somewhat limited because of the available computational resources.…”

“…Perhaps the most notable are specific heat, phase transitions, thermal expansion, thermal conductivity, melting, and so on. The macroscopic thermodynamic properties [1][2][3][4][5][6][7][8][9][10][11] are determined by microscopic crystalline and electronic structure and atomic vibrations, and these are determined by the nature of bonding between the atoms. In this book, we focus on the understanding and modeling of these microscopic and macroscopic properties and the experimental techniques [12][13][14][15][16][17][18][19][20][21] used in their investigation.…”

“…The modeling of the structure, dynamics, and various thermodynamic properties is done either by the first-principles quantum mechanical methods [6,7] or by the semiempirical methods [8][9][10][11] largely based on models of interatomic interactions. The former is computationally far more intensive; therefore, its application to complex structures has been more recent and somewhat limited because of the available computational resources.…”

“…These spectroscopic techniques [12-17] generate a rich amount of complex data of all kinds of vibrational modes of various polarizations and symmetry. Theoretical lattice dynamical calculations [7][8][9][10] are necessary for optimal planning of the experiments and for the microscopic interpretation of complex experimental data. Macroscopic measurements of specific heat [18] and thermal expansion [19,20] and use of high-pressure, high-temperature devices [21] are also particularly important for thermodynamic investigations.…”