Growth of 4He-Crystals at mK-Temperatures
Growth of 4He-Crystals at mK-Temperatures
复制标题
mK 温度下 4He 晶体的生长
DOI：
10.1023/a:1022246029056
复制
发表时间：
1998
影响因子：
2
通讯作者：
G. Tvalashvili
中科院分区：
文献类型：
--
作者：
J. Ruutu;P. Hakonen;A. Babkin;A. Parshin;G. Tvalashvili
本文用光学干涉仪和灵敏压力计研究了~ 4 He的液-固界面。每平方厘米有5-100个螺位错的小平面以螺旋生长的方式生长，这可以通过将惯性项和台阶局部化到标准理论来理解。没有螺位错的晶体揭示了两种新的生长机制。当生长速率> 1 nm/s时，这些高质量的晶体以爆发式的方式生长，突然产生了200-2000个新的原子层。在低于0.5nm/s的速率下，小面显示缓慢、连续的生长。研究ofa-刻面产生了速度与压力的依赖关系，这可以解释为螺旋生长。小面的形状被监测到2 mK，没有任何证据表明扭结的冻结。压力测量下降到我们的最低温度没有显示任何异常与超固体转变。在低至2 mK时未观察到新的小面过渡迹象。
Liquid-solid interface of4He has been investigated down to mK-temperatures using an optical interferometer in combination with a sensitive pressure gauge. Thec-facets with 5–100 screw dislocations/cm2grew with spiral growth which can be understood by including inertial terms and localization of steps to the standard theory. Crystals without screw dislocations revealed two novel growth mechanisms. At growth rates > 1 nm/s, these high-quality crystals grew in a burst-like manner, creating abruptly 200–2000 new atomic-layers. At rates below 0.5 nm/s, thec-facet revealed slow, continuous growth. Studies ofa-facets yielded a velocity vs. pressure dependence which can be explained by spiral growth. The shape of thec-facet was monitored down to 2 mK without any evidence of the freezing of kinks. Pressure measurements down to our minimum temperature did not show any anomalies connected with the supersolid transition. Indications of new faceting transitions were not observed down to 2 mK.