Use of focused ion beams for making tiny sample holes in gaskets for diamond anvil cells

To achieve multimegabar pressures in the diamond anvil cell, small diamond tips, 20 mu m (or less) in diameter and high strength gasket materials are required. To prevent plastic instability it is therefore necessary to drill sample holes with diameters of 10 mu m (or less) in extremely strong and t ough materials such as tungsten. The present paper describes a technique fo r drilling such holes using focused ion beams. The superior roundness and s urface finish of these holes is one of the reasons our group was able to re ach pressures of 342 GPa on hydrogen, significantly higher than that reache d by other researchers. (C) 2000 American Institute of Physics. [S0034-6748 (00)05101-7].