Physical vapor deposition of a polyamorphic system

In a few recently investigated systems, physical vapor deposition (PVD) has been shown to produce glasses that transform into liquids with properties that differ from the liquid produced by melting the crystal. Here we use PVD to investigate triphenyl phosphite (TPP), a known polyamorphic system where the second amorphous state (glacial phase) can be obtained by annealing the ordinary liquid (liquid 1) for hours slightly above its glass transition temperature (205 K). The properties of PVD glasses of TPP and the liquids formed from these glasses are studied by alternating current nanocalorimetry and interdigitated electrode dielectric spectroscopy. Deposition between 0.75 and 0.95 T_g results in glasses with very high kinetic stability. Independent of substrate temperature, the liquid that results from transforming the deposited glasses displays the properties of liquid 1, the ordinary liquid. Interestingly, films deposited above T_g also grow as liquid 1 even at temperatures previously used to transform liquid 1 into the glacial phase. The PVD mechanism allows the bulk of the film to inherit the structure at the free surface. These results suggest the preferred surface structure of TPP is similar to the structure of liquid 1, irrespective of deposition temperature.