Lan, T; Li, Chen W; Fultz, B Physical Review B, 86 (13), pp. 134302, 2012. Abstract | Links | BibTeX | Tags: anharmonicity, first-principles, phonon, Raman @article{lan_phonon_2012, title = {Phonon anharmonicity of rutile SnO 2studied by Raman spectrometry and first principles calculations of the kinematics of phonon-phonon interactions}, author = {T Lan and Chen W Li and B Fultz}, url = {https://link.aps.org/doi/10.1103/PhysRevB.86.134302}, doi = {10.1103/PhysRevB.86.134302}, year = {2012}, date = {2012-10-01}, journal = {Physical Review B}, volume = {86}, number = {13}, pages = {134302}, abstract = {Raman spectra of rutile tin dioxide (SnO$_2$) were measured at temperatures from 83 to 873 K. The pure anharmonicity from phonon-phonon interactions was found to be large and comparable to the quasiharmonicity. First-principles calculations of phonon dispersions were used to assess the kinematics of three-phonon and four-phonon processes. These kinematics were used to generate Raman peak widths and shifts, which were fit to measured data to obtain the cubic and quartic components of the anharmonicity for each Raman mode. The $B_2g$ mode had a large quartic component, consistent with the symmetry of its atom displacements. The broadening of the $B_2g$ mode with temperature showed an unusual concave-downwards curvature. This curvature is caused by a change with temperature in the number of down-conversion decay channels, originating with the wide band gap in the phonon dispersions.}, keywords = {anharmonicity, first-principles, phonon, Raman}, pubstate = {published}, tppubtype = {article} } Raman spectra of rutile tin dioxide (SnO$_2$) were measured at temperatures from 83 to 873 K. The pure anharmonicity from phonon-phonon interactions was found to be large and comparable to the quasiharmonicity. First-principles calculations of phonon dispersions were used to assess the kinematics of three-phonon and four-phonon processes. These kinematics were used to generate Raman peak widths and shifts, which were fit to measured data to obtain the cubic and quartic components of the anharmonicity for each Raman mode. The $B_2g$ mode had a large quartic component, consistent with the symmetry of its atom displacements. The broadening of the $B_2g$ mode with temperature showed an unusual concave-downwards curvature. This curvature is caused by a change with temperature in the number of down-conversion decay channels, originating with the wide band gap in the phonon dispersions. |
Li, Chen W; McKerns, M M; Fultz, B A Raman Spectrometry Study of Phonon Anharmonicity of Zirconia at Elevated Temperatures Journal Article Journal of the American Ceramic Society, 94 (1), pp. 224-229, 2010. Abstract | Links | BibTeX | Tags: anharmonicity, high temperature, oxide, phonon, Raman @article{li_raman_2010, title = {A Raman Spectrometry Study of Phonon Anharmonicity of Zirconia at Elevated Temperatures}, author = {Chen W Li and M M McKerns and B Fultz}, url = {http://doi.wiley.com/10.1111/j.1551-2916.2010.04057.x}, doi = {10.1111/j.1551-2916.2010.04057.x}, year = {2010}, date = {2010-01-01}, journal = {Journal of the American Ceramic Society}, volume = {94}, number = {1}, pages = {224-229}, abstract = {Raman spectra of monoclinic zirconia (ZrO2) were measured at temperatures of up to 950 K. Temperature‐dependent Raman peak shifts and broadenings were reported and compared with prior results on hafnia...}, keywords = {anharmonicity, high temperature, oxide, phonon, Raman}, pubstate = {published}, tppubtype = {article} } Raman spectra of monoclinic zirconia (ZrO2) were measured at temperatures of up to 950 K. Temperature‐dependent Raman peak shifts and broadenings were reported and compared with prior results on hafnia... |
Li, Chen W; McKerns, M M; Fultz, B Raman spectrometry study of phonon anharmonicity of hafnia at elevated temperatures Journal Article Physical Review B, 80 (5), pp. 1745, 2009. Abstract | Links | BibTeX | Tags: anharmonicity, high temperature, oxide, phonon, Raman @article{li_raman_2009, title = {Raman spectrometry study of phonon anharmonicity of hafnia at elevated temperatures}, author = {Chen W Li and M M McKerns and B Fultz}, url = {https://link.aps.org/doi/10.1103/PhysRevB.80.054304}, doi = {10.1103/PhysRevB.80.054304}, year = {2009}, date = {2009-08-01}, journal = {Physical Review B}, volume = {80}, number = {5}, pages = {1745}, abstract = {Raman spectra of monoclinic hafnium oxide $(textbackslashtextHfO_2)$ were measured at temperatures up to 1100 K. Raman peak shifts and broadenings are reported. Phonon dynamics calculations were performed with the shell model to obtain the total and partial phonon density of states, and to identify the individual motions of Hf and O atoms in the Raman modes. Correlating these motions to the thermal peak shifts and broadenings, it was found that modes involving changes in oxygen-oxygen bond length were the most anharmonic. The hafnium-dominated modes were more quasiharmonic and showed less broadening with temperature. Comparatively, the oxygen-dominated modes were more influenced by the cubic term in the interatomic potential than the hafnium-dominated modes. An approximately quadratic correlation was found between phonon-line broadening and softening.}, keywords = {anharmonicity, high temperature, oxide, phonon, Raman}, pubstate = {published}, tppubtype = {article} } Raman spectra of monoclinic hafnium oxide $(textbackslashtextHfO_2)$ were measured at temperatures up to 1100 K. Raman peak shifts and broadenings are reported. Phonon dynamics calculations were performed with the shell model to obtain the total and partial phonon density of states, and to identify the individual motions of Hf and O atoms in the Raman modes. Correlating these motions to the thermal peak shifts and broadenings, it was found that modes involving changes in oxygen-oxygen bond length were the most anharmonic. The hafnium-dominated modes were more quasiharmonic and showed less broadening with temperature. Comparatively, the oxygen-dominated modes were more influenced by the cubic term in the interatomic potential than the hafnium-dominated modes. An approximately quadratic correlation was found between phonon-line broadening and softening. |
Physical Review B, 86 (13), pp. 134302, 2012. |
A Raman Spectrometry Study of Phonon Anharmonicity of Zirconia at Elevated Temperatures Journal Article Journal of the American Ceramic Society, 94 (1), pp. 224-229, 2010. |
Raman spectrometry study of phonon anharmonicity of hafnia at elevated temperatures Journal Article Physical Review B, 80 (5), pp. 1745, 2009. |