High-temperature neutron diffraction experiment above 15 GPa using MA6-8

Sano, Asami   ; Hattori, Takanori   ; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*

Neutron diffraction provides us unique information in the investigation of the structure of materials under high-pressure. However, high-temperature experiments above 10 GPa have not been successful so far because of the conflicting requirements of a sample volume and a sufficient thermal insulation in an internal heater assembly. To overcome this difficulty and extend the accessible PT range, we applied a 6-8 type multi-anvil assembly (MA6-8) to a neutron diffraction experiment. The experiments were conducted using the 6-axis multi-anvil press in the high- pressure neutron diffractometer PLANET. A test with NaCl as an internal pressure standard shows that the pressure reaches to 16 GPa. We also observed the synthesis of CaSiO perovskite from the starting material of wollastonite after the heating at 1100 C at 16 GPa for 3 hours. The results demonstrate the potential utility of the MA6-8 to high temperature experiments.