Seminars

PIER Photon Science Colloquium: Earth and planetary interiors as seen by X-ray through diamond window

by Leonid Dubrovinsky (GeoInstitut Bayreuth)

Europe/Berlin
CFEL, Bldg. 99 (DESY Hamburg)

CFEL, Bldg. 99

DESY Hamburg

Description
The impact of high-pressure studies on fundamental physics and chemistry, and especially on the Earth and planetary sciences, has been enormous. While experiments in diamond anvil cells (DACs) at pressures of ∼250 - 400 GPa are proven to be very difficult but possible, at higher static pressures any matter has not been investigated until very recently. We have developed a method of synthesis of balls and semi-balls (of 10 to 50 μm in diameter) made of nanodiamond (with individual nano-particles of linear dimensions below 30 nm) and used them as second-stage or indentor-type anvils in conventional DACs. In experiments on rhenium, osmium, gold, platinum, and tungsten we were able to generate pressures above 700 GPa and demonstrated crucial necessity of the ultra-high pressure measurements for accurate determination of the equation of state of materials at extreme conditions.