Measurements and theoretical estimates are presented of the liquid-gas phase diagram of an electron-hole fluid in pure germanium. The critical point is found to occur in a region where the fluid is an electron-hole plasma at $T_c=6.5\mathrm{}\pm 0.1$ K and $n_c=(8\mathrm{}\pm 2)\times {10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$.

• Received 21 May 1974

DOI:https://doi.org/10.1103/PhysRevLett.33.219