Experimental studies of transplutonium metals and compounds under pressure
The structural behavior of the first four transplutonium metals and two Bk-Cf alloys as a function of pressure has been studied in diamond anvil cells via x-ray diffraction. The sequence of structures exhibited as pressure is increased is dhcp ..-->.. ccp ..-->.. orthorhombic. In addition a distorted ccp phase is observed in Am, Bk/sub 0.40/Cf/sub 0.60/, and Cf between the ccp and orthorhombic phases. Diamond anvil cells have also been used to contain AmI/sub 3/, CfBr/sub 3/, and CfCl/sub 3/ under pressure for investigation by absorption spectrophotometry. Both AmI/sub 3/ and CfBr/sub 3/ exhibit pressure-induced, irreversible phase transformations to the PuBr/sub 3/-type orthorhombic structure, a more dense form of these compounds. Thus the driving force for these transformations is more efficient crystal packing. Both hexagonal (to 22 GPa) and orthorhombic (to 35 GPa) CfCl/sub 3/ exhibit only reversible spectral changes with pressure. This probably reflects their nearly identical RTP unit cell volumes. In both cases the spectra obtained are consistent with a continuous alteration of the RTP structure with pressure; physical compression seems to make a given f-f transition easier. Additional data are being sought to elucidate more completely the behavior of CfCl/sub 3/ under pressure. 23 refs., 4 figs.
- Research Organization:
- Oak Ridge National Lab., TN (USA); Tennessee Univ., Knoxville (USA). Dept. of Chemistry; Commission of the European Communities, Karlsruhe (Germany, F.R.). European Inst. for Transuranium Elements
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 7151465
- Report Number(s):
- CONF-860911-20; ON: DE87002421
- Resource Relation:
- Conference: 192. American Chemical Society national meeting, Anaheim, CA, USA, 7 Sep 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMERICIUM IODIDES
ABSORPTION SPECTROSCOPY
MOLECULAR STRUCTURE
PHASE TRANSFORMATIONS
BERKELIUM ALLOYS
X-RAY DIFFRACTION
CALIFORNIUM BROMIDES
CALIFORNIUM CHLORIDES
CUBIC LATTICES
HCP LATTICES
ORTHORHOMBIC LATTICES
PRESSURE EFFECTS
VERY HIGH PRESSURE
ACTINIDE COMPOUNDS
ALLOYS
AMERICIUM COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CALIFORNIUM COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
HALIDES
HALOGEN COMPOUNDS
HEXAGONAL LATTICES
IODIDES
IODINE COMPOUNDS
SCATTERING
SPECTROSCOPY
TRANSPLUTONIUM COMPOUNDS
TRANSURANIUM COMPOUNDS
400102* - Chemical & Spectral Procedures