Comparison of Ion‐Beam Irradiation Effects in X2YO4 Compounds
Comparison of Ion‐Beam Irradiation Effects in X2YO4 Compounds
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X2YO4 化合物的离子束辐照效果比较
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
R. Ewing
中科院分区：
文献类型：
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作者：
Luming Wang;W. Gong;Shi Xin Wang;R. Ewing
使用原位和高分辨率透射电子显微镜（HRTEM）研究了1.5 MeV氪离子照射对橄榄石（A 2 VI B B IV O 4）、尖晶石（A IV B 2 VI O 4）和钠闪石结构的七种X 2 YO 4相的影响。在很宽的温度范围内（20-873 K）。在低温（<200 K）下，橄榄石和菲钠闪石易发生辐射诱导的非晶化，其临界非晶化剂量为0.2-0.5位移/原子（dpa）。临界非晶化剂量随辐照温度的增加而增加，各相的辐照速率不同，导致各相的临界非晶化温度不同。对于Mg-Fe系列橄榄石，在较高温度（室温或更高温度）下非晶化的敏感性随着Fe含量的增加而增加。虽然尖晶石相一般来说更不易非晶化，但高压亚稳尖晶石相γ-SiFe 2 O 4在低于723 K的温度下，剂量<0.2dpa时很容易非晶化。该相在873 K辐照后分解。在20 K下，FeCr 2 O 4尖晶石（铬铁矿）在10.4dpa时完全非晶化，而MgAl 2 O 4尖晶石在5.4dpa时没有观察到非晶化的迹象。这些阶段的非晶化的相对敏感性的明显差异进行了讨论的非晶化过程中的结构和化学控制。
The effects of 1.5 MeV Kr-ion irradiation on seven X 2 YO 4 phases with the olivine (A 2 VI B IV O 4 ), spinel (A IV B 2 VI O 4 ), and phenakite structures have been investigated using in situ and high-resolution transmission electron microscopy (HRTEM) over a wide temperature range (20-873 K). At low temperatures (<200 K), the olivine and phenakite are susceptible to radiation-induced amorphization with a critical amorphization dose of 0.2-0.5 displacement per atom (dpa). The critical amorphization dose increases with increasing irradiation temperature at varying rates for the various phases, resulting in a distinct critical amorphization temperature for each phase. For the Mg-Fe series of olivine, the susceptibility to amorphization at higher temperatures (room temperature or above) increases with increasing Fe content. Although the spinel phases are, in general, much more resistant to amorphization, a highpressure metastable spinel phase, γ-SiFe 2 O 4 , is easily amorphized at doses <0.2 dpa at temperatures below 723 K. This phase decomposes after irradiation at 873 K. At 20 K, complete amorphization of the FeCr 2 O 4 spinel (chromite) is achieved at ∼4 dpa, but no evidence of amorphization is observed in MgAl 2 O 4 spinel after 5.4 dpa. The distinct differences in the relative susceptibility of these phases to amorphization are discussed in terms of the structural and chemical controls on the amorphization process.