A miniature cubic anvil apparatus for optical measurement under high pressure

A miniature cubic anvil apparatus was developed for optical measurement on materials in a high-pressure space of 8-10 mm(3) under high pressure, and preliminary experiments were conducted to 3.6 GPa at room temperature with optical visual observation and ruby fluorescence measurement. In the apparatus, a cubic pressure medium was squeezed with six tungsten carbide anvils, which are driven with a pair of guide blocks by tightening four loading screws. Optical access on the sample was made through holes in axial anvils and the guide blocks as well as optical windows made of Al(2)O(3) single crystals embedded in the pressure medium. The apparatus is compact and light, ~53 mm in diameter and height and ~530 g in weight, and the features of the apparatus benefit easy application of the apparatus to various types of standard optical measurement systems. The optical measurement on the sample in the high-pressure space of 8-10 mm(3) should greatly contribute to advancements of studies relevant to high-pressure behaviors of materials.