“…Studies of Gibbs energy changes associated with copper phosphide formation consist entirely of vapor pressure studies. The partial pressure of P 4 in equilibrium with CuP 2 and Cu 3 P has been measured by Haraldsen (873-1073 K) and by Ugai et al (963-1173 K) 133,222 using static method techniques; the agreement between the results is impressive. Combining the two results, for In addition to this, Gordienko and Viksman reported the partial pressure of P 4 generated by the decomposition of Cu 3 P. 221 However, the temperatures at which values are reported (1178, 1238, and 1292 K) are higher than the Cu/Cu 3 P eutectic in Figure 17, making the data unusable for calculating assessed thermodynamic properties for Cu 3 P (and thus for CuP 2 as well).…”