Stabilization of Nanocrystalline Copper by Tantalum Grain Boundary Segregation

Nanocrystalline Cu-Ta alloy films were deposited on glass slides by magnetron sputtering. Microstructure characterization proved that most of the tantalum atoms are segregated in the grain boundaries. Nanoindentation creep measurements were performed on it to uncover the stability mechanism of grain boundary segregation on nanocrystalline materials. It is found that segregation can effectively slow down the creep strain rate and the grain boundary activities. The suppressed grain boundary activities endow the alloy with a stable microstructure during plastic deformation and annealing.

环戊并二噻吩衍生物的合成及其应用

环戊并二噻吩衍生物作为一类具有刚性平面的类芴骨架结构的分子,其光电材料衍生物由于具有带隙低、电导率高和良好的电荷传输性能等优点在塑料电子领域有着广泛的应用.同时由于其易于进行结构修饰,能够方便、快捷地引入各种功能基团,可拓展合成多种衍生物.依据环戊并二噻吩上噻吩S原子的位置不同,可以将其分为6种构造异构体.在这些构造异构体中,目前关于4H-环戊[2,1-b:3,4-b']二噻吩衍生物的研究报道较多.作者对4H-环戊[2,1-b:3,4-b']二噻吩衍生物的合成、性质及其在有机太阳能电池(OSCs)、有机场效应晶体管(OFETs)、有机发光二极管(OLEDs)等领域的研究进展进行了全面综述,并对其有机半导体的格子化学进行了展望.