ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The Mössbauer effect in129I in conjunction with Diamond-Anvil-Cell high pressure techniques was applied to investigate the high pressure phase(s) of the molecular crystal GeI4. The129IQuadrupole Interaction was the main probe for characterizing theintermolecular structural transformation with pressure. With increasing pressure, at about 15 GPa, the onset of a partial molecular-association phase (HP1) is first observed. In HP1 two out of the four iodines strongly overlap to form linear chains of GeI4. The HP1 phase coexists with the low pressure (LP) molecular phase, but its population increases with increasing pressure. AtP=20 GPa a second high pressure phase (HP2) is identified where all four iodines strongly overlap to form a three dimensional, fully molecular-associated structure. With increasing pressure and atP〉20 GPa, HP2 is the only phase up toP=34 GPa, the highest pressure used. A significant hysteresis of the relative abundances with pressure is observed. The isomer shift of the HP2 and HP1 structures is considerably larger than that of the LP one.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02101071
