通过射频磁控溅射法制备了系列Ti Al CN涂层。研究结果表明,通过调节溅射过程中N2流量,Ti Al CN涂层的组成和结构均发生明显变化。很小的N2流量会导致Ti Al CN涂层的晶体结构发生显著变化。随着N2流量的增加,涂层物相组成由fcc-（Ti Al...通过射频磁控溅射法制备了系列Ti Al CN涂层。研究结果表明,通过调节溅射过程中N2流量,Ti Al CN涂层的组成和结构均发生明显变化。很小的N2流量会导致Ti Al CN涂层的晶体结构发生显著变化。随着N2流量的增加,涂层物相组成由fcc-（Ti Al）C相转变为更为复杂的fcc-（Ti Al）（CN）相,同时析出hcp-（Al Ti）（CN）新相。N2流量的进一步增加使得涂层物相最终转变为以hcp-（Al Ti）（CN）为主导的相结构。此外,N2流量还会促进涂层中非晶碳的析出。N2流量为0.5 m L/min时,Ti Al CN涂层由于多相共存,晶粒显著细化,尺寸约为10~20 nm,此时涂层具有较好的力学性能和摩擦学性能。展开更多
Hexagonal-phase NaYF4：Yb3＋,Er3＋ upconversion nanoparticles（UCNPs） with a uniform size distribution were synthesized using rare-earth acetates as precursors. The effects of reaction temperature and time on the pha...Hexagonal-phase NaYF4：Yb3＋,Er3＋ upconversion nanoparticles（UCNPs） with a uniform size distribution were synthesized using rare-earth acetates as precursors. The effects of reaction temperature and time on the phase transition process of the UCNPs were systematically studied. Based on the evolution of particle morphology and phase with temperature and time, it could be concluded that the transition from cubic phase to hexagonal phase for NaYF4：Yb3＋,Er3＋ UCNPs was consistent with a dissolution/recrystallization process. In addition, the shape and size of the UCNPs could be controlled by adjusting the solvent ratio and the precursor ratio, respectively.展开更多
文摘通过射频磁控溅射法制备了系列Ti Al CN涂层。研究结果表明,通过调节溅射过程中N2流量,Ti Al CN涂层的组成和结构均发生明显变化。很小的N2流量会导致Ti Al CN涂层的晶体结构发生显著变化。随着N2流量的增加,涂层物相组成由fcc-（Ti Al）C相转变为更为复杂的fcc-（Ti Al）（CN）相,同时析出hcp-（Al Ti）（CN）新相。N2流量的进一步增加使得涂层物相最终转变为以hcp-（Al Ti）（CN）为主导的相结构。此外,N2流量还会促进涂层中非晶碳的析出。N2流量为0.5 m L/min时,Ti Al CN涂层由于多相共存,晶粒显著细化,尺寸约为10~20 nm,此时涂层具有较好的力学性能和摩擦学性能。
基金Project supported by the National Natural Science Foundation of China(51302038)the Natural Science Foundation of Jiangsu Province of China(BK2011064,BK2012346)
文摘Hexagonal-phase NaYF4：Yb3＋,Er3＋ upconversion nanoparticles（UCNPs） with a uniform size distribution were synthesized using rare-earth acetates as precursors. The effects of reaction temperature and time on the phase transition process of the UCNPs were systematically studied. Based on the evolution of particle morphology and phase with temperature and time, it could be concluded that the transition from cubic phase to hexagonal phase for NaYF4：Yb3＋,Er3＋ UCNPs was consistent with a dissolution/recrystallization process. In addition, the shape and size of the UCNPs could be controlled by adjusting the solvent ratio and the precursor ratio, respectively.
