Abstract
The high-pressure and high-temperature behaviors of LiF and NaF have been studied up to 37 GPa and 1000 K. No phase transformations have been observed for LiF up to the maximum pressure reached. The B1 to B2 transition of NaF at room temperature was observed at ∼28 GPa, this transition pressure decreases with temperature. Unit-cell volumes of LiF and NaF B1 phase measured at various pressures and temperatures were fitted using a P–V–T Birch–Murnaghan equation of state. For LiF, the determined parameters are: α0 = 1.05 (3)×10−4 K−1, dK/dT = −0.025 (2) GPa/K, V 0 = 65.7 (1) Å3, K 0 = 73 (2) GPa, and K′ = 3.9 (2). For NaF, α0 = 1.34 (4)×10−4 K−1, dK/dT = −0.020 (1) GPa/K, V 0 = 100.2 (2) Å3, K 0 = 46 (1) GPa, and K′ = 4.5 (1).
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Acknowledgements
Financial support was provided by the DFG, grant BO 2550/1-1.