Abstract:
In microcalorimetry for measuring heats of adsorption on clean single-crystal surfaces, a pulse of gas from a molecular beam adsorbs on an ultrathin single crystal's surface, causing a measurable transient heat input and temperature rise. One new and sensitive method of heat detection uses a 9 mu m pyroelectric polymer ribbon, which is mechanically driven to make a gentle mechanical/thermal contact to the back of the single-crystal sample during measurement (J.T. Stuckless, N.A. Frei, C.T. Campbell, A novel single-crystal adsorption calorimeter and additions for determining metal adsorption and adhesion energies, Rev. Sci. Instr. 69, 1998, 2427-2438). Here we describe simulations of the signal pulse shape and an analysis of absolute signal intensities, based on system parameters such as the detector pyroelectric coefficient and thermal conductivities of the detector and sample, in order to understand heat collection efficiency in this and related calorimetric techniques. © 2000 Elsevier Science S.A. All rights reserved.

Author Keywords:
calorimetry, adsorption, pyroelectric sensors, ultra-high vacuum, heat flow

Addresses:
Stuckless JT, Univ British Columbia, Dept Chem, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada.
Univ Washington, Dept Chem, Seattle, WA 98195 USA.

Publisher:
ELSEVIER SCIENCE SA, LAUSANNE

IDS Number:
274JP

ISSN:
0925-4005