High-resolution x-ray diffraction with diamond-anvil cells, using argon as a quasi-hydrostatic pressure medium, documents the crystal structure and equation of state of osmium to over 60 GPa at room temperature. We find the zero-pressure bulk modulus in fair agreement with other experiments as well as with relativistic electronic band-structure calculations: Osmium is the densest but not the most incompressible element at ambient conditions. We also find no evidence for anomalies in the ratio of unit-cell parameters, c/a, or in the compressibility of osmium as a function of pressure. This is in agreement with other experiments and quantum mechanical calculations but disagrees with recent claims that the electronic structure and equation of state of osmium exhibit anomalies at pressures of ∼15-25 GPa; the discrepancies are may be due to the effects of texturing.
|Number of pages||5|
|Journal||Journal of Applied Physics|
|Publication status||Published - 1 Jun 2012|
|Event||2012 American Institute of Physics - College Park, US, College Park|
Duration: 9 Nov 2012 → 12 Nov 2012