Very high temperature diamond-anvil cell for X-ray diffraction: Application to the comparison of the gold and tungsten high-temperature-high-pressure internal standards
1987; American Geophysical Union; Linguagem: Inglês
10.1029/gm039p0075
ISSN2328-8779
AutoresDavid Schiferl, J. N. Fritz, A. I. Katz, M. W. Schaefer, E. F. Skelton, S. B. Qadri, L. C. Ming, Murli H. Manghnani,
Tópico(s)Geological and Geochemical Analysis
ResumoA high-temperature high-pressure diamond-anvil cell which has been used previously for X-ray diffraction at over 10 GPa and 1500 K is described. The materials of the cell are listed in a table along with the physical and chemical criteria for choosing them. A major improvement is the use of rhenium gaskets, which are difficult to fabricate but which have worked nearly perfectly during extensive testing. Because the diffraction pattern of Re sometimes interferes with that of the Au in situ high-temperature-high-pressure standard, W is proposed as another such standard. A table of isochores in P, T space for W derived from ultrasonic, Shockwave and thermal expansion data is presented. Comparison of X-ray diffraction data from W and Au up to 1300 K shows that there is fairly good agreement between the two standards. However, as the temperature is raised, the pressure according to the Au scale becomes increasingly greater than that from the W scale. Previous workers have reported similar behavior of Au in comparison to other materials at simultaneous high temperatures and pressures. While none of these results are conclusive, it is clear that more careful cross-comparisons of the various high-temperature high-pressure standards are required to establish them with confidence.
Referência(s)