Measurement and calculation of the pressure dependence of the Mössbauer isomer shift of metallicSn119for the pressure range0≤P≤310kbar

We have measured the pressure dependence of the Mössbauer isomer shift S(P) for tin for the pressure range 0≤P≤310 kbar through the use of a diamond anvil pressure cell. Also, S(P) has been calculated for this pressure range using a relativistic augmented-plane-wave model. In these calculations, a Kohn-Sham, a Hedin-Lundqvist, or a Slater model was used to describe the electron-electron interaction. A Dirac-Hartree-Wigner-Seitz model was used to calculate the muffin-tin potential. For the 92-kbar phase transition, the calculated change of the electron density at the tin nucleus was found to be roughly independent of whichever of the above models was used to describe the electron many-body interaction. Based on this, a value for the Mössbauer isomer-shift calibration constant of 0.072$a_0^3$ mm/sec, and an approximate description of the measured S(P) for the above pressure range is obtained. A comparison of our results with other measurements and calculations is made.