Temperature dependence of ion irradiation damage in the pyrochlores La2Zr2O7 and La2Hf2O7
Temperature dependence of ion irradiation damage in the pyrochlores La2Zr2O7 and La2Hf2O7
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DOI：
10.1088/0953-8984/16/47/009
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发表时间：
2004-12
期刊：
影响因子：
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通讯作者：
G. Lumpkin;K. Whittle;S. Ríos;Katherine L. Smith;N. Zaluzec
中科院分区：
文献类型：
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作者：
G. Lumpkin;K. Whittle;S. Ríos;Katherine L. Smith;N. Zaluzec
在阿贡国家实验室用1.0 MeV的Kr2+在中压电子显微镜（IVEM-Tandem Facility）中对高温超导体La2Zr2O7和La2Hf2O7的合成样品进行了原位辐照。这项研究的结果表明，这两个pyroxylores通过结晶-非晶转变，虽然有显着不同的临界非晶化剂量曲线。外推到0 K（Dc0）的临界剂量值为La2Zr2O7的11 ± 3 × 1014 ions cm − 2（dpa）和La2Hf2O7的5.5 ± 0.7 × 1014 ions cm − 2（dpa）。剂量-温度曲线的非线性最小二乘分析给出了La2Zr2O7和La2Hf2O7的临界温度（Tc）值分别为339 ± 49 K和563 ± 10 K。该分析还给出了锆烧绿石和铪烧绿石的损伤热恢复的活化能（Ea）值分别为0.02 ± 0.01和0.05 ± 0.01 eV。这些结果表明，有一个主要的差异，在剂量-温度响应依赖于这两个焦磷酸盐的B-位阳离子的性质。结果进行了讨论，在烧绿石结构参数rA/rB和x（48 f），以及停止功率，位移能，和缺陷的能量的材料。
Synthetic samples of the pyrochlores La2Zr2O7 and La2Hf2O7 were irradiated in situ in the intermediate voltage electron microscope (IVEM-Tandem Facility) at Argonne National Laboratory using 1.0 MeV Kr2+. Results of this study demonstrate that both pyrochlores pass through the crystalline–amorphous transformation albeit with significantly different critical amorphization dose curves. The critical dose values extrapolated to 0 K (Dc0) are 11 ± 3 × 1014 ions cm−2 ( dpa) for La2Zr2O7 and 5.5 ± 0.7 × 1014 ions cm−2 ( dpa) for La2Hf2O7. Non-linear least squares analysis of the dose–temperature curves gave values of the critical temperature (Tc) of 339 ± 49 K for La2Zr2O7 and 563 ± 10 K for La2Hf2O7. This analysis also gave values of the activation energy (Ea) for thermal recovery of damage of 0.02 ± 0.01 and 0.05 ± 0.01 eV for the zirconium pyrochlore and the hafnium pyrochlore, respectively. These results demonstrate that there is a major difference in the dose–temperature response dependent upon the nature of the B-site cation of these two pyrochlores. Results are discussed in terms of the pyrochlore structural parameters rA/rB and x(48f) as well as the stopping powers, displacement energies, and defect energies of the materials.