Materials Properties at Very Low Temperatures

前三年的工作涉及动压- 3He集体模式的相关研究， 激发集体模式，UPt3中的声音传播， 极化~3He电池的研制、氧化物中的声传播 超导体，新牛津低温恒温器的安装， 薄膜超晶格的超导特性是 总结 特别重要的是， 超声波场依赖性的声学异常 UPt3中的信号衰减，其可能发信号通知一种新的相位 过渡 他们建议继续研究 3He的模式谱，包括非常短的路径长度，新颖的 激发方案、非线性效应和极化液体。 微波吸收研究在稀释中的重要性 冰箱区指出，UPt3的研究针对 集体模式的观察。 顶部装载 我们的牛津低温恒温器的磁强计改造建议，再次 重点是UPt3。

The work of the previous three years involving dynamic-pressure- dependent studies of collective modes in 3He, novel schemes to excite collective modes, sound propagation in UPt3, the development of a polarized 3He cell, sound propagation in oxide superconductors, the installation of a new-Oxford cryostat, and the superconducting properties of thin-film superlattices is summarized. Of particular importance was the characterization of an acoustic anomoly in the field dependence of the ultrasonic signal attenuation in UPt3 which may signal a new kind of phase transition. They propose continuing studies of the collective mode spectrum of 3He involving very short path lengths, novel excitation schemes, nonlinear effects, and the polarized liquid. The importance of microwave absorption studies in the dilution refrigerator region is noted and studies of UPt3 directed at the observation of collective modes are proposed. A top loading magnetometer alteration of our Oxford cryostat is proposed, again with the major emphasis on UPt3.