Brillouin scattering studies and computational simulations of the elastic properties of pyrite (FeS_2) at high temperatures

摘要

Surface Brillouin scattering has been used to study the variation of the velocities of the Rayleigh surface acoustic wave (RSAW) and the high frequency pseudo-SAW (HFPSAW) with azimuthal angle on the (110) surface of iron pyrite (FeS_2) over the temperature range 293 to 573 K. The elastic constants of this cubic compound, namely C_(11), C_(12) and C_(44) were extracted by the simultaneous fitting of the velocity data to the results of calculations using surface elastodynamic Green's functions and decrease gradually with increasing temperature. An interatomic potential model has been developed for iron pyrite and has been used to calculate the values of the elastic constants over the same range of temperature as the experimental results. There is good agreement between experimental and the computational results.