Roughening transition temperature in the presence of an adsorbing fluid

The effect on the roughening temperature TR of an adsorbing fluid above the substrate is calculated. The partition function is evaluated for three models, the Ising model, the absolute solid-on-solid model, and the discrete Gaussian models, with the addition of a second species in vapor form above the surface. Then with the use of the duality transformation of Jos\'e et al. and the renormalization-group method of Kosterlitz, a relationship between TR and the chemical potential of the fluid is obtained. TR is then expressed in terms of the ambient pressure by using approximate equations of state. It is found that a significant decrease in TR may occur as the pressure is increased, and the conditions under which this effect might be observed are discussed. .Ire ranges the heat capacity, thermal expansion, and heat conduction are calculated using the same parameters for the soliton representation as were used to calculate the temperature dependence of the proton spin-lattice relaxation time. Discontinuities in the thermal properties at the glass transition temperature Tg are attributed to an effective-mass change of the low-energy solitons. This work was conducted to test, with the use of nuclear magnetic resonance, some recent ideas in the dynamics of amorphous materials.