Matsoso Joyce B, Ranganathan Kamalakannan, Wamwangi Daniel, Erasmus Rudolph, Coville Neil J, Derry Trevor
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand Johannesburg 2050 South Africa
DSI-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand Johannesburg 2050 South Africa
Nanoscale Adv. 2025 Aug 28. doi: 10.1039/d5na00616c.
Solid carbon nanospheres of ∼200 nm diameter have been prepared and then doped by ion implantation, using a specialized end-station adapted for the uniform implantation of powders. Boron, nitrogen and neon ions were chosen, the latter for control purposes. Herein, the dependence of the physicochemical properties of solid carbon spheres on the fluence of the implanted ions was investigated by controlling the addition of the 100 keV of B, N or Ne ions into the carbon shell over 7 h and 14 h implantation periods at room temperature. SEM analysis revealed significant surface deformation in the form of cracks for the Ne implanted samples, whilst little structural deformation was observed with N and B implanted samples. Furthermore, TEM micrographs confirmed the dependence of the structural properties on the ion fluence. Finally, magnetic properties showed that the type of the hetero-ion as well as the affiliation of the carbon with the bonding configurations of the hetero-ion influenced the transition from diamagnetism to super-paramagnetism as absolute zero was approached. The Néel temperature varied somewhat but was below about 10 K. Boron conferred a much greater paramagnetic susceptibility at low temperature than the other ions and showed indications of a higher electrical conductivity at higher temperatures, suggesting an electronic doping effect. The study highlights the impact of the choice of the heteroatom ion on the properties of the solid carbon spheres for the development of next generation carbon-based electronic devices.
已经制备出直径约200 nm的固态碳纳米球，然后通过离子注入进行掺杂，使用专门的终端站以实现粉末的均匀注入。选择了硼、氮和氖离子，选择氖离子是出于对照目的。在此，通过在室温下7小时和14小时的注入时间内控制向碳壳中添加100 keV的硼、氮或氖离子，研究了固态碳球的物理化学性质对注入离子注量的依赖性。扫描电子显微镜（SEM）分析显示，注入氖离子的样品表面出现了明显的裂纹形式的变形，而注入氮和硼离子的样品几乎没有观察到结构变形。此外，透射电子显微镜（TEM）显微照片证实了结构性质对离子注量有依赖性。最后，磁性表明，杂离子的类型以及碳与杂离子键合构型的关联影响了在接近绝对零度时从抗磁性到超顺磁性的转变。奈尔温度有所变化，但低于约10 K。硼在低温下赋予的顺磁磁化率比其他离子大得多，并且在较高温度下显示出更高电导率的迹象，表明存在电子掺杂效应。该研究突出了杂原子离子的选择对固态碳球性质的影响，这对于下一代碳基电子器件的开发具有重要意义。
