4He adsorption isotherms on Na-plated Pyrex glass

Tuning the wetting transition: Prewetting and superfluidity ofHe4on thin cesium substrates

“…Only recently, however, it has become clear [2-4] that the phases and phase transitions of adsorbates on these weak binding substrates can be qualitatively different from those observed on conventional strong binding substrates, and several recent experiments [5][6][7][8] have confirmed novel behavior in alkali metal adsorption systems. These results have been especially provocative in the case of 4 He adsorption because alkali metals are the only known substrates which are not completely wet by superfluid helium, and also because this system is a particularly clear example of a more general type of surface phase transition known as prewetting [9,10].…”