Anomalous pressure-induced phase transformation in nano-crystalline erbium sesquioxide (Er₂O₃): partial amorphization under compression

Abstract

Nanophase materials have novel physical and chemical properties, differing from bulk materials. It is of exceptional interest to investigate the size effect on structural stability in nanocrystals. Here, we investigated pressure-induced phase transitions in nanosized Er₂O₃ using angle-dispersive synchrotron X-ray diffraction up to 40.6 GPa. Nano-Er₂O₃ has enhanced transition pressure and higher bulk modulus (K₀) than its bulk counterparts. Amorphous Er₂O₃ nanoclusters with traces of monoclinic phase are obtained upon compression. This is the first time that partial amorphous structure under compression was observed in nano-Er₂O₃, indicating a kinetic trapping of partial amorphous Er₂O₃ on pressurizing.

Keywords:

• nanocrystalline Er₂O₃
• synchrotron X-ray diffraction
• high pressure
• elevated transformation pressure
• partial amorphization

Acknowledgements

This work is supported by the Natural Science Foundation of China (Grant Nos. 11027405 and 10976018), China 973 Program (Grant No. 2011CB808200). The high pressure ADXD experiments were carried out at beam line 4W2 of the Beijing Synchrotron Radiation Facility (BSRF), which is supported by Chinese Academy of Sciences (Grant No. KJCX2-SW-N03, KJCX2-SW-N20). The authors thank Professor Yanzhang Ma, Texas Tech University for his useful discussion and advice. We thank Yanchun Li and Chuanlong Lin for experimental assistance.