Abstract
The elastic properties of ε-FeSi were investigated at high temperature and pressure using a combination of ultrasonic interferometry and synchrotron radiation up to 8 GPa and 1273 K. The unit-cell volumes and sound velocity data were fit to third-order finite-strain equations with adiabatic temperature conversions to maintain a thermodynamically internally consistent data set. The adiabatic zero-pressure bulk and shear moduli and their first pressure and temperature derivatives were obtained from this fitting: KS0 = 168.9(7) GPa, G0 = 116.5(3) GPa, KS0′ = 6.6(2), G0′ = 2.9(1), (∂KS0/∂T)P = -0.023(1) GPa/K, (∂G0/∂T)P = -0.030(1) GPa/K. This study presents the first complete thermodynamically consistent set of elastic moduli and their temperature and pressure derivatives.
© 2015 by Walter de Gruyter Berlin/Boston
