The concentration-dependent position of the diffuse peaks in electron and x-ray diffraction patterns of ${\mathrm{Cu}}_{1-x}{\mathrm{Pd}}_x$ alloys in the disordered state is attributed to Fermi surface nesting. We present the first experimentally determined Fermi surfaces of ${\mathrm{Cu}}_{0.72}{\mathrm{Pd}}_{0.28}$ and ${\mathrm{Cu}}_{0.6}{\mathrm{Pd}}_{0.4}$, and show that they do indeed possess significant flat areas capable of nesting. Moreover, the magnitudes of the nesting vectors are in excellent agreement with those deduced from electronic structure calculations and diffraction experiments.

• Received 26 March 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.216401