论文标题
超音速二进制N2-kR气流簇的形成和生长的电子衍射研究
Electron diffraction study of the formation and growth of clusters in supersonic binary N2-Kr gas jets
论文作者
论文摘要
在N2-KR二元喷气机中形成的无基质簇的电子衍射诊断，通过超音速喷嘴扩展到真空中。气体混合物含有0.5、1和6 mol。％k，簇束中的聚集的平均大小从每个簇的500至30,000分子不等。当喷气机构在喷嘴入口T0处的气体混合物的温度从100 k增加到120 K时，射流中的成核机制的变化被发现，这对簇的尺寸，相组成和成分组成产生了深远的影响。已经确定，插入的k核成核中心在T0 = 100 K时通过增加FCC相的分数来实现簇生长的强化。在T0 = 120 K时，首次揭示了添加具有明显强分子力的杂质来抑制簇生长的影响。结果表明，当klypton气体含量增加到6摩尔％，并且是由超音速射流中气体冷凝的动力学引起的。
An electron diffraction diagnostics of substrate-free clusters formed in N2-Kr binary jets expanding through a supersonic nozzle into vacuum was carried out. Gas mixtures contained 0.5, 1, and 6 mol.% krypton, the measured average sizes of aggregations in the cluster beam varied from 500 to 30,000 molecules per cluster. A change in the nucleation mechanism in the jet from heterogeneous to homogeneous was revealed when the temperature of the gas mixture at the nozzle inlet T0 increased from 100 K to 120 K, which had a profound effect on the sizes, phase composition and component composition of the clusters. It was established that the intensification of cluster growth by inserted krypton nucleation centers at T0 = 100 K occurs through an increase in the fraction of the fcc phase. At T0 = 120 K, the effect of cluster growth suppression by the addition of an impurity with significantly stronger intermolecular forces was revealed for the first time. It is shown that the effect is manifested when the krypton gas content increases to 6 mol.% and is caused by the kinetics of gas condensation in a supersonic jet.
