Theory of Supercooled Liquids; Phase Diagram of Water; Orientational Dependent Interactions.
Abstract
Part 1: We investigated the question whether one can conclude from BBGKY theories whether instabilities do occur in a liquid at low temperatures. Several authors denied this possibility and we show that such results are due to the assumptions they made. Part 2: In order to calculate the phase diagram of water we introduce a lattice model that has the following features. A nearest neighbor attraction, which is strongly dependent on the relative orientation of water molecules, due to hydrogen bonding and a next nearest neighbor or three body repulsion. The hydrogen bonding is introduced with the help of a set of weight factors in accordance with Pauling's ice rules. The entropy is calculated according to the cluster variation method for tetrahedrons. The isotherms show a maximum in the density and a phase separation between the vapor, the open ice state and a state which is dense packed. Part 3: To see how orientational dependent forces influence the supercooling process, the simplest model known (Barker and Fock model) is analysed. It is shown under what conditions the phase diagram becomes topologically different from the simple Ising phase diagram. Part 4: Preparatory work for the determination of the characteristic points in the phase diagram of an antiferromagnet. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- ADA077377
Entities
People
- Paul H. E. Meijer
Organizations
- The Catholic University of America