Pressure effect on the Fermi surfaces of Ag and Cu

Abstract

The effect of pressure on the detailed shape of the Fermi surfaces of Ag and Cu has been investigated by a measurement of the transverse magnetoresistance of high purity single crystals at 4·2°K and 18 kilogauss under hydrostatic pressures up to 2·5 kilobar. No change in size of the ‘necks’ relative to the rest of the Fermi surface was observed in either metal. The precision was such that a change of about 0·2% per kilobar and 0·3% per kilobar could have been detected in Cu and Ag respectively. A theoretical estimate based on Ziman's model for the noble metals gives a change just less than the limits of detection in our experiment. A technique for obtaining single crystal wires with resistance ratios (R _300°K/R _4°K) in the range 1000–1500 is outlined.