NH₃−H₂O co-deposition experiments. All experiments were performed on a gold substrate. The TPDs had a ramp of 0.2 K s⁻¹. The solid lines represent the desorption of NH₃, while the dashed-dotted lines represent the desorption of water. Lines of the same colour belong to the same set of experiments. Inset: TPD of NH₃ from a gold surface used to calibrate all the subsequent experiments.