Fermi-surface imaging effect in the D short-range order of PdDx

A Fermi-surface imaging effect is proposed to explain the concentration-dependent D short-range order in the vicinity of the (1, 1/2 ,0) point of PdD_x with 0.7<x<0.78. Within a rigid-band approximation the shape of the Fermi surface in PdD_0.75 is deduced from that calculated by Gupta and Freeman for stoichiometric PdH. In PdD_0.75 the obtained Fermi surface shows flat portions and 2k_F vectors close to the (1, 1/2 ,0) points.