Dielectric Constant of GaP at 1.6°K

A comparison of observed and calculated line positions in a donor-acceptor pair spectrum yields a value of $\epsilon \mathrm{}\left(0\right)=10.75\mathrm{}\pm 0.1$ for the GaP static dielectric constant at 1.6°K. Earlier analyses of pair spectra assumed $\epsilon \mathrm{}\left(0\right)=11.1\mathrm{}$, the value obtained from Raman-scattering measurements at 300°K. The new value of $\epsilon \mathrm{}\left(0\right)\mathrm{}$ necessitates a small revision in the ionization energies of some donors and acceptors.