First-Order Isostructural Phase Transition Induced by High Pressure in Fe(IO3)3
The high-pressure (HP) behavior of Fe(IO3)3 was studied up to 35 GPa using powder X-ray diffraction, infrared micro-spectroscopy, and ab initio density-functional theory calculations. Fe(IO3)3 show...
Pressure-Driven Symmetry-Preserving Phase Transitions in Co(IO3)2
[EN] High-pressure synchrotron X-ray diffraction studies of cobalt iodate, Co(IO3)(2), reveal a counterintuitive pressure-induced expansion along certain crystallographic directions. High-pressure Raman and infrared spectroscopy, combined with density-functional theory calculations, reveal that with increasing pressure, it becomes energetically favorable for certain I-O bonds to increase in length over the full range of pressure studied up to 28 GPa. This phenomenon is driven by the high-pressure behavior of iodate ion lone electron pairs. Two pressure-induced isosymmetric monoclinic-monoclinic phase transitions are observed at around 3.0 and 9.0 GPa, which are characterized by increasing o…