We have developed a low-temperature, ac microcalorimeter for exploring
adsorption on a single 2.25 mm2 graphite leaf that is capable of
10 picoJoule/degree resolution. The microcalorimeter was used to
determine the phase diagram and heat capacity critical exponents
agr of monolayer4He films at the commensurate ordering transition.
After in situ baking at 600 K, we reproduced the narrow-ordered phase
region (sime1% in coverage) reported by Campbell and Bretz for HOPG,
but find quasilogarithmic, rather than power law, heat capacity divergences.
We argue that the disappearance of the Potts-like exponent in the
heat capacity is attributable to the geometry of nucleation along
cleavage edge planes present on single crystal graphite surfaces.
%0 Journal Article
%1 Chae1989
%A Chae, H. B.
%A Bretz, Michael
%D 1989
%J Journal of Low Temperature Physics
%K microcalorimetry; resistance, science, sensor; surface thermistor;
%P 199-223
%R 10.1007/BF00681585
%T Microcalorimetry study of the monolayer4He ordering transition on
single crystal graphite
%V 76
%X We have developed a low-temperature, ac microcalorimeter for exploring
adsorption on a single 2.25 mm2 graphite leaf that is capable of
10 picoJoule/degree resolution. The microcalorimeter was used to
determine the phase diagram and heat capacity critical exponents
agr of monolayer4He films at the commensurate ordering transition.
After in situ baking at 600 K, we reproduced the narrow-ordered phase
region (sime1% in coverage) reported by Campbell and Bretz for HOPG,
but find quasilogarithmic, rather than power law, heat capacity divergences.
We argue that the disappearance of the Potts-like exponent in the
heat capacity is attributable to the geometry of nucleation along
cleavage edge planes present on single crystal graphite surfaces.
@article{Chae1989,
abstract = {We have developed a low-temperature, ac microcalorimeter for exploring
adsorption on a single 2.25 mm2 graphite leaf that is capable of
10 picoJoule/degree resolution. The microcalorimeter was used to
determine the phase diagram and heat capacity critical exponents
agr of monolayer4He films at the commensurate ordering transition.
After in situ baking at 600 K, we reproduced the narrow-ordered phase
region (sime1% in coverage) reported by Campbell and Bretz for HOPG,
but find quasilogarithmic, rather than power law, heat capacity divergences.
We argue that the disappearance of the Potts-like exponent in the
heat capacity is attributable to the geometry of nucleation along
cleavage edge planes present on single crystal graphite surfaces.},
added-at = {2009-10-30T10:04:05.000+0100},
author = {Chae, H. B. and Bretz, Michael},
biburl = {https://www.bibsonomy.org/bibtex/2430dafb654658893d0dd15ddc06346fa/jfischer},
doi = {10.1007/BF00681585},
interhash = {29ab8743a6511d0bbd7cc47725dc6065},
intrahash = {430dafb654658893d0dd15ddc06346fa},
journal = {Journal of Low Temperature Physics},
keywords = {microcalorimetry; resistance, science, sensor; surface thermistor;},
pages = {199-223},
timestamp = {2009-10-30T10:04:10.000+0100},
title = {Microcalorimetry study of the monolayer4He ordering transition on
single crystal graphite},
volume = 76,
year = 1989
}