The complex structural behavior of strontium under high pressure has been studied using angle-dispersive x-ray powder-diffraction techniques. The previously unknown structure of Sr-IV is found to be monoclinic, with space group Ia and 12 atoms per unit cell, and is a helical distortion of the β-tin structure of Sr-III. This structure has not been observed before in an element. Sr-IV is stable from 37.7(2)0.3em0exGPa0.3em0exto0.3em0ex46.3(3)0.3em0exGPa where it transforms to the composite incommensurate Sr-V phase. Diffraction patterns over the small range from 36.00.3em0exto0.3em0ex37.70.3em0exGPa cannot be fitted completely by either Sr-III or Sr-IV. The previously identified minority phase of unknown structure that appears at the Sr-II to Sr-III transition persists through Sr-IV and Sr-V.
No takes yet. Share an insight, caveat, or question.
Bovornratanaraks et al. (2006) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: