Synchrotron X-ray powder diffraction experiments at high pressure conditions (0.0001-13 GPa) were performed at ESRF (Grenoble-F), on the beamline ID9, to investigate the bulk elastic properties of natural P2/n- omphacites, with quasi-ideal composition. The monoclinic cell parameters a, b, c and β were determined as a function of pressure, and their compressibility coefficients are 0.00277(7), 0.00313(8), 0.00292(5) and 0.00116(4) GPa-1, respectively. The third-order BirchMurnaghan equation of state was used to interpolate the experimental P - V data, obtaining Ko = 116.6 (±2.5) GPa and K1o = 6.03 (±0.60). Ko was also determined by means of the axial and angular compressibilities [122.5(±1.7) GPa], and of the finite Lagrangian strain theory [121.5(±1.0) GPa]. The discrepancies on Ko are discussed in the light of a comparison between techniques to determine the bulk modulus of crystalline materials from static compression diffraction data.
|Titolo:||Synchrotron X-ray powder diffraction study of natural P2/n omphacites at high pressure conditions|
PAVESE, ALESSANDRO (Primo)
|Settore Scientifico Disciplinare:||Settore GEO/06 - Mineralogia|
|Data di pubblicazione:||2001|
|Digital Object Identifier (DOI):||10.1007/s002690000128|
|Appare nelle tipologie:||01 - Articolo su periodico|