Solid ammonium fluoride has fascinating structural similarities with water ice, despite its ionic character. Here, the authors investigate NH4F at room temperature and high pressure, and report a new tetragonal phase formed through displacive transition of fluorine ions and subsequent rotation of ammonium ions in ‘antiferromagnetic’ units at ~115 GPa, which is unlike any form of ice.
- Umbertoluca Ranieri
- Christophe Bellin
- Livia E. Bove
