TY - JOUR
T1 - Pressure induced phase transition of nanocrystalline and bulk maghemite (γ-Fe2O3) to hematite (α-Fe2O 3)
AU - Zhu, Hongyang
AU - Ma, Yanzhang
AU - Yang, Haibin
AU - Ji, Cheng
AU - Hou, Dongbin
AU - Guo, Lingyun
N1 - Funding Information:
We thank Jingzhu Hu and Quanzhong Guo for their technical support with the synchrotron X-ray diffraction measurements at Brookhaven National Laboratory, and Trevor Hannon for proofreading the manuscript. This work is supported by the National Science Foundation (NSF) grant number DMR-0619215, the Defense Threat Reduction Agency (DTRA) grant number HDTRA 1–09–0034, and the Army Research Office (ARO) grant number W911NF-09–1–0001.
PY - 2010/8
Y1 - 2010/8
N2 - Phase transition and bulk moduli of bulk and nanocrystalline γ-Fe2O3 were studied using synchrotron X-ray diffraction under high pressure. Contrary to most other nanomaterials, nanocrystalline γ-Fe2O3 begins to transform into α-Fe2O3 at the same pressure as bulk γ-Fe 2O3, which is caused by a special structure of γ-Fe2O3, in which there exist vacancies of crystal. It is believed that phase transition starts from a certain site of vacancy because of the stress concentration at vacancy sites. Compared to bulk material, nanocrystalline γ-Fe2O3 has a larger bulk modulus, which is ascribed to the large ratio of surface to volume.
AB - Phase transition and bulk moduli of bulk and nanocrystalline γ-Fe2O3 were studied using synchrotron X-ray diffraction under high pressure. Contrary to most other nanomaterials, nanocrystalline γ-Fe2O3 begins to transform into α-Fe2O3 at the same pressure as bulk γ-Fe 2O3, which is caused by a special structure of γ-Fe2O3, in which there exist vacancies of crystal. It is believed that phase transition starts from a certain site of vacancy because of the stress concentration at vacancy sites. Compared to bulk material, nanocrystalline γ-Fe2O3 has a larger bulk modulus, which is ascribed to the large ratio of surface to volume.
KW - C. High Pressure
KW - C. X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=77955559900&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2010.03.031
DO - 10.1016/j.jpcs.2010.03.031
M3 - Article
AN - SCOPUS:77955559900
SN - 0022-3697
VL - 71
SP - 1183
EP - 1186
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
IS - 8
ER -