Pressure Induced Structural Transformation in Gd2Ti2O7 and Gd2Zr2O7

Journal Article · Wed Jan 05 04:00:00 EST 2011 · Journal of Physics. Condensed Matter, 23(3):Article No. 035501

DOI:https://doi.org/10.1088/0953-8984/23/3/035501· OSTI ID:1007359

Xiao, Haiyan Y; Weber, William J

Ab initio total energy calculations have been performed to study the phase stability of Gd2Ti2O7 and Gd2Zr2O7 pyrochlores over the pressure range from 0 to 60 GPa. Both compounds are unstable under pressure, and phase transformations to the defect-cotunnite structure are predicted. The phase transformation pressure of 43.6 GPa for Gd2Ti2O7 is considerably larger than the value of 13 GPa for Gd2Zr2O7, in good agreement with experiments. The decreased structural stability of Gd2Zr2O7 under pressure, relative to Gd2Ti2O7, is a consequence of the lower compressibility of the langZr–Orang bond and the higher compressibility of the langGd–Orang bond. In addition, the Gd 4f electrons are found to have only a small effect in determining the pressure induced phase transformation.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1007359
• Journal Information: Journal of Physics. Condensed Matter, 23(3):Article No. 035501, Journal Name: Journal of Physics. Condensed Matter, 23(3):Article No. 035501
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory