ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Heat capacities (C) of 3 He submonolayer solids adsorbed on a graphite surface are measured down to 100 μK, a factor of twenty lower temperatures than previous work. At a real densities near the commensurate $$\sqrt 3 \times \sqrt 3 $$ solid (6.4 nm −2 ), an anomalous temperature dependence, C ∝ 1/T, is observed in a wide temperature range over two orders of magnitude (0.1 ≤ T ≤ 20mK). Similar behavior was observed for the commensurate $$\sqrt 7 \times \sqrt 7 $$ solid in the second-layer with the same density, suggesting a common microscopic mechanism. It is, however, a puzzle that the $$\sqrt 3 \times \sqrt 3 $$ solid is ferromagnetic according to recent magnetization measurements by ISSP group, while the $$\sqrt 7 \times \sqrt 7 $$ solid is known to be antiferromagnetic. Possible explanations for this conflict, such as vacancy effects or multiple-spin exchanges modulated by a substrate potential corrugation, are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022542415432
