Introduction

Experimental Setup

Data

Discussion

Results

References

Experimental Setup

The quartz microbalance technique used to monitor the adsorbed coverage is conventional [5-7, 9]. Adsorption takes place on the gold electrodes of the microbalance, which were used as received from the manufacturer. The main experimental challenge in these studies is to provide a uniform thermal environment. The microbalance was mounted in a cell inside two concentric radiation shields. The cell and the inner shield were made of gold-plated copper to minimize thermal gradients. Our thermometers were calibrated by measuring the saturated vapor pressure to locate the bulk triple point, using a cell connected to a heated fill line. The data reported here, however, were obtained using a cell which was loaded with gas at room temperature and then sealed to entirely eliminate the heated fill line. The amount of gas was sufficient to ensure that several mm³ of bulk phase formed near T_t.