Raman spectroscopic study of PbCO3 at high pressures and temperatures

Journal Article · Fri May 22 04:00:00 EDT 2009 · Physics and Chemistry of Minerals

OSTI ID:1041137

Minch, R; Ehm, L

Cerussite (PbCO{sub 3}) has been investigated by high-pressure and high-temperature Raman spectroscopy up to pressures of 17.2 GPa and temperatures of 723 K. Two pressure induced phase transitions were observed at about 8.0(2) and 16.0(2) GPa, respectively. The post-aragonite transition (PbCO{sub 3}-II) at 8.0(2) GPa is accompanied by softening of the v 2-out-of-plane mode of the CO{sub 3}{sup 2-} group and disappearance of the B{sub 1g} (v{sub 4}-in-plane band of the CO{sub 3}{sup 2-} group) mode. Stronger shifts of the carbonate group modes after the phase transition suggest that the new structure is more compressible. The formation of a second high-pressure polymorph begins at about 10 GPa. It is accompanied by the occurrence of three new bands at different pressures and splitting of the v{sub 1}-symmetric C-O stretching mode of the CO{sub 3}{sup 2-} group. The transitions are reversible on pressure release. A semi-quantitative phase diagram for PbCO{sub 3} as a function of pressure and temperature is proposed.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1041137
• Report Number(s): BNL--90949-2010-JA; KC0204011
• Journal Information: Physics and Chemistry of Minerals, Journal Name: Physics and Chemistry of Minerals Journal Issue: 1 Vol. 37; ISSN 0342-1791; ISSN PCMIDU
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CARBONATES
PHASE DIAGRAMS
PRESSURE RELEASE
RAMAN SPECTROSCOPY