  Diamond anvil cell using boron-doped metallic diamond electrodes covered with
undoped diamond insulating layer have been developed for electrical transport
measurements under high pressure. These designed diamonds were grown on a
bottom diamond anvil via a nanofabrication process combining microwave
plasma-assisted chemical vapor deposition and electron beam lithography. The
resistance measurements of high quality FeSe superconducting single crystal
under high pressure were successfully demonstrated by just putting the sample
and gasket on the bottom diamond anvil directly. The superconducting transition
temperature of FeSe single crystal was enhanced up to 43 K by applying
uniaxial-like pressure.
