The high pressure(P)-high temperature(T) phase diagram of solid ammonia has been investigated using diamond anvil cell and resistive heating techniques. The III-IV transition line has been determined up to 20 GPa and 500 K both on compression and decompression paths. No discontinuity is observed at the expected location for the III-IV-V triple point. The melting line has been determined by visual observations of the fluid-solid equilibrium up to 9 GPa and 900 K. The experimental data is well fitted by a Simon-Glatzel equation in the covered P-T range. These transition lines and their extrapolations are compared with reported calculations.
@article{arxiv.0801.0913,
title = {High pressure-high temperature phase diagram of ammonia},
author = {Sandra Ninet and Frédéric Datchi},
journal= {arXiv preprint arXiv:0801.0913},
year = {2009}
}