Phase separation in solid mixtures of helium-3 and helium-4
Phase separation in solid mixtures of helium-3 and helium-4
复制标题
氦 3 和氦 4 固体混合物中的相分离
DOI：
10.1007/bf00682625
复制
发表时间：
1987
影响因子：
2
通讯作者：
R. Simmons
中科院分区：
文献类型：
--
作者：
S. Ehrlich;R. Simmons
从X射线晶格参数和布拉格峰形的变化测量中，确定了bcc ~ 3 He-~ 4 He混合物的相分离温度随~ 3 He浓度和熔化压力的变化。采用一种新型的刚性尾稀释制冷机低温恒温器，对3 He浓度为0.10、0.20、0.30、0.45、0.60和0.70，熔化压力为3.0 ~ 4.3MPa的3 He-4 He晶体进行了研究。确定的相分离温度是在良好的协议与正规溶液理论，并给出一个不对称的共存曲线的Nosanow型模型，并从以前的实验报告使用其他签名相分离的支持。在一个给定的浓度，从缓慢冷却和升温的数据，分别确定的相分离温度的差异，是多达25毫度，但这是从以前的实验报告的差异的一半以下。在3.7MPa的熔化压力下，含10%3He的晶体在T = 0.3K左右发生bcc-hcp相变。
Phase separation temperatures have been determined in bcc3He-4He mixtures as a function of3He concentration and melting pressure from measurements of changes in the X-ray lattice parameter and Bragg peak shape. A new rigid tail dilution refrigerator cryostat was used to study3He-4He crystals with3He concentrations of 0.10, 0.20, 0.30, 0.45, 0.60, and 0.70 and melting pressures between 3.0 and 4.3 MPa. The phase separation temperatures determined are in good agreement with regular solution theory and give little support for an asymmetry in the coexistence curve expected from a Nosanow-type model and reported from previous experiments using other signatures of phase separation. At a given concentration, differences in phase separation temperatures determined from slow cooling and warming data, respectively, are as much as 25 mdeg, but this is less than half the differences reported from previous experiments. A bcc-hcp transformation was seen in a crystal with 10%3He at aboutT=0.3 K for a melting pressure of3.7 MPa.