Opposed-anvil-type high-pressure and high-temperature apparatus using sintered diamond

An opposed-anvil-type high-pressure and high-temperature apparatus is developed, adopting sintered diamond as the anvil material. Pressures and temperatures up to about 30 GPa and 1700 K can be achieved routinely without difficulty. The use of a metal gasket dramatically reduces the occurrence of blowouts and results in very stable pressure generation. By improving the preparation methods and materials used for the small components of the sample assembly, experiments can be performed much more easily than with previous versions of the apparatus. Pressures and temperatures were measured by in situ x-ray diffraction using two different pressure markers. Temperatures of the sample were also estimated from the resistance change of the heater. Estimated pressure and temperature conditions were checked by the phase transformation of Al-bearing MgSiO3 and were consistent with the stability field of the perovskite phase as previously reported. Compared to the laser-heated diamond anvil cell, this apparatus has the advantage of uniform temperature and a much larger sample volume. As a result, the new apparatus has major advantages for studying multicomponent systems and the partitioning of the elements. (c) 2006 American Institute of Physics.