X-RAY DIFFRACTION EVIDENCE FOR A CRITICAL END POINT FOR CERIUM I AND CERIUM II

Journal Article · Wed Apr 01 04:00:00 EST 1964 · Phys. Chem. Solids

DOI:https://doi.org/10.1016/0022-3697(64)90003-4· OSTI ID:4014630

Davis, B L; Adams, L H

A beryllium pressure vessel was used to investigate the two face- centered phases of cerium at various temperatures and pressures along the phase boundary. X-ray diffraction records of the strong 111 peak of both pbases show that the two peaks. coalesce with increasing temperature and pressure along the boundary. The P-t region for the critical end point of the boundary is obtained by extrapolation of the change in d-spacing with distance along the boundary, and is found to be 350--400 deg C and 20--22 kb. The x-ray data also show that the compressibility and thermal expansion of the high-pressure (II) phase are greater than those of the low-pressure (I) phase. Rate studies indicate that under pressure phase I persists into the phase H stability field with lowering temperature. Considerable overstepping of pressure into this fleld is also possible before complete transformation of I-II will take place. (auth)

• Research Organization: Univ. of California, Los Angeles
• NSA Number: NSA-18-020551
• OSTI ID: 4014630
• Journal Information: Phys. Chem. Solids, Journal Name: Phys. Chem. Solids Vol. Vol: 25
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALLOTROPY
ANGULAR DISTRIBUTION
ANISOTROPY
ATOMIC MODELS
BERYLLIUM
CERIUM
COMPTON EFFECT
CRYSTALS
DIFFRACTION
ELECTRONS
ENERGY LEVELS
EXCITATION
EXPANSION
GRAIN BOUNDARIES
HARTREE-FOCK METHOD
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
MONOCRYSTALS
NUMERICALS
PHONONS
PRESSURE
PRESSURE VESSELS
ROTATION
SCATTERING
SELF-CONSISTENT FIELD
SILICON
SOUND
TEMPERATURE
VELOCITY
X RADIATION