Study of Quadrupole Interactions in Nano LaFeO3 Perovskites by Time Differential Perturbed Angular Correlation
doi: 10.11804/NuclPhysRev.22.01.054
- Received Date: 1900-01-01
- Rev Recd Date: 1900-01-01
- Publish Date: 2005-03-20
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Key words:
- TDPAC /
- quadrupole interaction /
- LaFeO3 nano material
Abstract: The quadrupole interactions in the nanoand crystalline LaFeO3 perovskites have been investigated by TDPAC. The TDPAC probing nuclei 14057La14058Ce were produced through the nuclear reaction 139La(n.γ)140La at the CIAE heavy water experimental reactor. One electric quadrupole interaction was detected for each material, which is assigned to the La site. The quadrupole interaction frequencies of 687.4, 698.3 and 742.9 Mrad/s with a distribution coefficient of 0.014, 0.009 and 0.001 were observed at room temperature for the 20 and 40 nm nanoLaFeO3 and crystalline LaFeO3, respectively. The fitting yielded the EFG asymmetry parameter η=0, which indicates that the principal axes of the EFG is aligned with the crystallographic axes. The experimental results show that the structure of crystalline LaFeO3 is rhombohedral, the changing of the structure towards the orthorhombic structure takes place from the crystalline LaFeO3 to the nanoLaFeO3, and the smaller the nanograin size, the larger the change. The frequency distribution is caused by the perturbation of the neighboring atoms, and thus, the distribution coefficient increases with decreasing the nanograin size and the crystalline LaFeO3 arrives at its maximum.
Citation: | DU En-peng, GE Zhi-gang, ZHENG Yong-nan, ZHOU Dong-mei, ZUO Yi, YUAN Da-qing, WANG Ping-sheng, DUAN Xiao, SHI Hai-song, WANG Jian-bo, LI Fashen, ZHU Sheng-yun. Study of Quadrupole Interactions in Nano LaFeO3 Perovskites by Time Differential Perturbed Angular Correlation[J]. Nuclear Physics Review, 2005, 22(1): 54-57. doi: 10.11804/NuclPhysRev.22.01.054 |