ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
Results are reported of an investigation using synchrotron radiation into the effects of temperatures up to 1173 K on pressure-induced phase transitions in phosphorus. A cubic type multi-anvil press was employed and a diffraction pattern in an energy-dispersive mode was taken for a period of time, typically 200 s, without suffering from a deterioration of the sample material. The pressure of the first transition, orthorhombic–rhombohedral (As-type), decreases with increasing temperature at a rate of 2.3 MPa K−1 and the As-type structure is stable at a pressure as low as 2.6 GPa at a temperature of 1073 K. The volume discontinuity at the transition, ΔV, is 10% at room temperature and remains almost unchanged with increasing temperature. The axial ratio c/a, when the rhombohedral structure is referred to the hexagonal system, changes mostly with pressure but only slightly with temperature, approaching √6 = 2.45 on going to the second transition, rhombohedral–simple cubic. The pressure of this transition, in contrast to the first one, is independent of temperature but ΔV at this transition, 3.7%, continuously decreases with increasing temperature.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889887086394
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