PYROELECTRIC SINGLE-CRYSTAL ADSORPTION MICROCALORIMETRY AT LOW-TEMPERATURES - OXYGEN ON NI(100)

The prototype single crystal adsorption microcalorimeter developed in our laboratory utilises remote temperature sensing by infrared radiation and is currently restricted to substrates at room temperature. A new pyroelectric detection scheme has now been developed which can be used at low substrate temperatures. The first low temperature calorimetric results are presented, for oxygen on Ni{100}, together with sticking probability measurements. Significant differences are observed between substrate temperatures of 100 and 300 K; these are discussed in terms of differences in precursor mobility and 0 adatom distribution in the adlayers.