Melting of corundum (α-Al2O3) under compression to 8 GPa: A decreasing melting slope
Abstract
Melting of corundum (α-Al2O3) has been studied under compression up to 8 GPa using in situ electrical resistivity measurements. The melting temperature increases monotonically from T0 = 2317 K at ambient pressure to 3090 K at 7.7 GPa. Fitting the experimental data to the Simon-Glatzel equation yields the empirical parameters a = 5.60 GPa and c = 0.334, providing a closed-form analytical description of the entire melting boundary. Most significantly, the melting slope, dTm/dp, decreases continuously from 138 K/GPa at ambient pressure down to 78 K/GPa at 7.7 GPa, confirming unequivocal negative curvature of the melting curve (d2Tm/dp2 < 0). This phenomenon is consistent with the preferential densification of the liquid phase and the associated reduction in the volume change upon melting as pressure rises. These findings provide a robust empirical standard for the high-pressure melting of corundum, establishing essential constraints for future ab initio simulations, thermodynamic databases, and geophysical models of alumina-rich deep-Earth systems.
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BibTeX
@misc{solozhenko2026melting,
title = {{Melting of corundum (α-Al2O3) under compression to 8 GPa: A decreasing melting slope}},
author = {Vladimir L. Solozhenko},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.19229},
eprint = {2609.19229},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.19229},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Melting of corundum (α-Al2O3) under compression to 8 GPa: A decreasing melting slope
AU - Vladimir L. Solozhenko
PY - 2026
DA - 2026/09/16
PB - arXiv
DO - 10.48550/arxiv.2609.19229
UR - https://arxiv.org/abs/2609.19229
AB - Melting of corundum (α-Al2O3) has been studied under compression up to 8 GPa using in situ electrical resistivity measurements. The melting temperature increases monotonically from T0 = 2317 K at ambient pressure to 3090 K at 7.7 GPa. Fitting the experimental data to the Simon-Glatzel equation yields the empirical parameters a = 5.60 GPa and c = 0.334, providing a closed-form analytical description of the entire melting boundary. Most significantly, the melting slope, dTm/dp, decreases continuously from 138 K/GPa at ambient pressure down to 78 K/GPa at 7.7 GPa, confirming unequivocal negative curvature of the melting curve (d2Tm/dp2 < 0). This phenomenon is consistent with the preferential densification of the liquid phase and the associated reduction in the volume change upon melting as pressure rises. These findings provide a robust empirical standard for the high-pressure melting of corundum, establishing essential constraints for future ab initio simulations, thermodynamic databases, and geophysical models of alumina-rich deep-Earth systems.
ER -