New single-toroidal sintered diamond anvil and assembly for high pressure neutron diffraction

Abstract

In-situ high pressure neutron diffraction experiments, which require a large volume samples, remain challenging, particularly when generating simultaneous high pressure-temperature (P-T) conditions. Although high pressure neutron diffraction experiments have been successfully extended to pressures exceeding 20 GPa, generating pressures over 10 GPa with a large sample volume in the millimeter scale is still difficult. Based on the strategy of introducing gaskets in multi-anvil press, a new single-toroidal sintered diamond anvil and high P-T assembly have been designed for use in the Paris-Edinburgh press, to promoting the neutron diffraction technique with a broadened P-T range. This new single-toroidal set-up can achieve pressure exceeding 14 GPa, with a pressure generating efficiency is nearly same as that of double-toroidal anvil, and exhibits remarkable stability during high P-T experiments. The high P-T neutron diffraction experiments demonstrate that the new set-up can achieves a pressure of 8.7(1) GPa and a temperature of 1380(15) K with a large sample volume of 38 mm³.