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Crystal structure of solid Oxygen at high pressure and low temperature

Federico A. Gorelli·Mario Santoro·Lorenzo Ulivi·Michael Hanfland
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Abstract

Results of X-ray diffraction experiments on solid oxygen at low temperature and at pressures up to 10 GPa are presented.A careful sample preparation and annealing around 240 K allowed to obtain very good diffraction patterns in the orthorhombic delta-phase. This phase is stable at low temperature, in contrast to some recent data [Y. Akahama et al., Phys. Rev. B64, 054105 (2001)], and transforms with decreasing pressure into a monoclinic phase, which is identified as the low pressure alpha-phase. The discontinuous change of the lattice parameters, and the observed metastability of the alpha-phase increasing pressure suggest that the transition is of the first order.

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Federico A. Gorelli, Mario Santoro, Lorenzo Ulivi, Michael Hanfland. 2001-11-21. Crystal structure of solid Oxygen at high pressure and low temperature. https://doi.org/10.1103/physrevb.65.172106

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