Effect of doping on the radiation response of conductive Nb-SrTiO3
Effect of doping on the radiation response of conductive Nb-SrTiO3
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DOI：
10.1016/j.nimb.2013.03.010
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发表时间：
2013-05-01
影响因子：
1.3
通讯作者：
Ewing, Rodney C.
中科院分区：
文献类型：
--
作者：
Li, Weixing;Rodriguez, Matias D.;Ewing, Rodney C.
基于库仑尖峰模型，径迹的形成强烈地依赖于材料的电阻率，并且离子径迹仅在绝缘材料中形成。然而，没有系统的研究电阻率对材料中的径迹形成的影响，例如SrTiO 3（STO），其中添加低浓度的Nb，覆盖从绝缘到导电材料的整个电子状态的电阻率显著降低。在这项研究中，高能量（8.6 MeV/u）的离子诱导轨道形成STO的特点是通过透射电子显微镜（TEM）和小角X射线散射（SAXS）技术作为Nb掺杂浓度的函数。与库仑尖峰模型的预测相反，Nb掺杂对径迹形成没有明显的影响，正如TEM和SAXS所证实的那样。这可能是体材料中的低电子密度或Nb掺杂对材料中的键合的较小影响的结果。低能量（1 MeV Kr 2+）离子辐照的原位TEM研究表明，低浓度掺杂对晶体到非晶的转变有轻微的影响，作为一个结果的微妙的结构变化的杂质原子。(C)2013爱思唯尔有限公司版权所有。
Based on the Coulomb spike model, track formation depends strongly on the electrical resistivity of a material, and ion tracks form only in insulating materials. However, there are no systemic studies of the effect of resistivity on the track formation in materials, such as SrTiO3 (STO), where with the addition of low concentrations of Nb, the resistivity dramatically decreases covering the entire electronic regime from an insulating to conducting material. In this study, high energy (8.6 MeV/u) ion-induced track formation in STO was characterized by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) techniques as a function of Nb-doping concentrations. Contrary to the Coulomb spike model's predictions, the Nb-doping had no evident influence on track formation, as confirmed by both TEM and SAXS. This may be the result of the low electron density in the bulk material or the minor effect of the Nb-doping on the bonding in the material. In situ TEM studies of low energy (1 MeV Kr2+) ion irradiations show that the low concentration doping has a minor influence on the crystalline-to-amorphous transformation as a result of subtle structural variations of incorporated impurity atoms. (C) 2013 Elsevier B.V. All rights reserved.