In-situ synthesis of carbon capsulated Ni nanoparticles and their cooperative doping effects on superconducting properties of MgB2
In-situ synthesis of carbon capsulated Ni nanoparticles and their cooperative doping effects on superconducting properties of MgB2
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碳包覆Ni纳米粒子的原位合成及其协同掺杂对MgB2超导性能的影响
DOI：
10.1016/j.jallcom.2016.04.287
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发表时间：
2016-10
影响因子：
6.2
通讯作者：
Shihai Cui
中科院分区：
文献类型：
--
作者：
Qian Zhao;Chunjian Jiao;Zheng Zhu;Zhuo Chen;Shihai Cui
采用化学气相沉积（CVD）技术，成功地在B基体中原位合成了平均粒径为7 ~ 8 nm的碳包覆镍纳米颗粒，解决了传统混合方法导致纳米颗粒团聚的问题。在模型体系的基础上，研究了CVD技术对碳收率、形貌和结构的影响，并在750℃下制备了含3.8、8.2和8.5 wt%碳的（MgB2）（0.96）Ni-0.04块体。x射线衍射图显示，在合成过程中，Ni没有取代Mg， C也没有取代B。而TEM分析表明，这种具有核壳结构的装饰插入物在MgB2基质内是稳定的，由于尺寸小，有望起到钉钉中心的作用。在我们的实验中，虽然沉积过程中大量的MgO杂质抑制了纳米颗粒的优势，但在低场范围内观察到J(c)的小幅增强，这表明通过诱导均匀的纳米颗粒细化MgB2晶粒，提高了晶粒的连通性。因此，在控制MgO含量的情况下，可以进一步获得理想的高场J(c)性能。
Carbon-encapsulated Ni nanoparticles (the average diameter of the particles is 7-8 nm) in B matrix were successfully in situ synthesized by chemical vapor deposition (CVD) in order to solve the agglomeration of nanoparticles by traditional mixing method. The influences of CVD technique on the carbon yield, morphology and structure were well investigated based on model system, and the (MgB2)(0.96)Ni-0.04 bulks containing 3.8, 8.2 and 8.5 wt% carbon were prepared at 750 degrees C. The X-ray diffraction patterns showed no substitution of Ni for Mg and less substitution of C for B during the synthesis process, whereas the TEM analysis suggested such decorated insertions with core-shell structure were stable within the MgB2 matrix and hopefully acted as pinning center due to the small size. In our experiment, although the advantage of nanoparticles was suppressed by the large amount of MgO impurities during the deposition process, a small enhancement of J(c) was observed in the low field range, which indicated improved grain connectivity because of the refinement of MgB2 grains by inducing homogeneous nanoparticles. In view of this, a desirable J(c) performance at high field could be further obtained under the control of MgO content.
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影响因子：
6
作者：
W. Yeoh;R. Zheng;S. Ringer;Wenxian Li;Xun Xu;S. Dou;S. Chen;J. MacManus‐Driscoll
通讯作者：
W. Yeoh;R. Zheng;S. Ringer;Wenxian Li;Xun Xu;S. Dou;S. Chen;J. MacManus‐Driscoll
影响因子：
6.2
作者：
B. Jun;Jung Ho Kim;Chan-Joong Kim;K. Choo
通讯作者：
B. Jun;Jung Ho Kim;Chan-Joong Kim;K. Choo
影响因子：
29.4
作者：
Sihai Zhou;A. Pan;D. Wexler;S. Dou
通讯作者：
Sihai Zhou;A. Pan;D. Wexler;S. Dou
影响因子：
6.2
作者：
Q. Cai;Yong-chang Liu;Zongqing Ma;Liming Yu;J. Xiong;Huijun Li
通讯作者：
Q. Cai;Yong-chang Liu;Zongqing Ma;Liming Yu;J. Xiong;Huijun Li
影响因子：
2.1
作者：
D. Patel;M. S. Hossain;A. Motaman;S. Barua;M. Shahabuddin;Jung Ho Kim
通讯作者：
D. Patel;M. S. Hossain;A. Motaman;S. Barua;M. Shahabuddin;Jung Ho Kim