Authors: Masashi Morishita
Publish Date: 2012/10/26
Volume: 171, Issue: 5-6, Pages: 664-669
Abstract
The heat capacity of dilute 3He–4He films is measured to clarify whether the second adsorbed layer of 4He films on graphite solidify into the socalled “4/7 phase” The 3He areal density is fixed at 02 nm−2 whereas the 4He areal density is gradually increased The measured heat capacities suddenly decrease with an increasing areal density approaching that of the 4/7 phase Above the areal density of the 4/7 phase the heat capacities do not reduce completely to zero and have finite values The behavior of the heat capacity does not change over a rather wide areal density regime although it suddenly increases or recovers at around the areal density of the thirdlayer promotion These behaviors can be interpreted as the separation of 3He–4He mixture films into a 3Herich phase and a 4Herich phase with the 3Herich phase solidifying into the 4/7 phase and the 4Herich phase remaining fluid below the areal density of the thirdlayer promotion These observations strongly suggest that a 4He film adsorbed on a graphite surface does not solidify into the 4/7 phaseAll experimental measurements were performed with commonly used equipment at the Cryogenics Division Research Facility Center for Science and Technology University of Tsukuba This research was supported by GrantsinAid for Scientific Research from the Ministry of Education Culture Sports Science and Technology Japan
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