Study of the efficiency of various anvils for dsDACs

Multiplication factors with respect to the confining pressure for all tested anvil shapes evaluated from both pressure determination methods, Raman spectroscopy (spectroscopy, triangles) and X-ray diffraction (diffraction, diamonds).

As the use of conventional diamond anvil cells is limited to ~ 400 GPa, there has been a recent development to extend the pressure range up to the terapascal by using secondary stage anvils and special shape designs. This extension enables state of the art high pressure research to investigate and understand not only Earth’ deep interior but also radical changes of properties under ultra-high pressure. Transitions from covalent to metallic bonding or insulator to superconductor are just two of many examples of already observed phenomena.

Within the scope of this project, several shapes of those secondary anvils are tested regarding their ability to generate a multiple of the applied pressure on the primary anvil and the pressure distribution on the stage’s surface. Therefore, Raman spectroscopy as well as synchrotron X-ray diffraction is used to determine pressure using the diamond peak shift or the EOS of Ir and Au, respectively.