Phase Diagrams P versus

Phase Diagrams (P versus T) 13-14 Amorphous Solids and Crystalline Solids 13-15 Structures of Crystals 13-16 Bonding in Solids 13-17 Band Theory of Metals... 

Fig. A.5-7A (NH4)3H(S04)2. T versus p phase diagram. p is the hydrostatic pressure. Phases VI and VII are ferroelectric...

Figure 11 Phase diagram T versus p for the model system /j, = 3.3 and v = 2. Squares Isotropic ordering (I) ...

Figure A2.5.1. Schematic phase diagram (pressure p versus temperature 7) for a typical one-component substance. The full lines mark the transitions from one phase to another (g, gas liquid s, solid). The liquid-gas line (the vapour pressure curve) ends at a critical point (c). The dotted line is a constant pressure line. The dashed lines represent metastable extensions of the stable phases.

Figure A2.5.10. Phase diagram for the van der Waals fluid, shown as reduced temperature versus reduced density p. . The region under the smooth coexistence curve is a two-phase liquid-gas region as indicated by the horizontal tie-lines. The critical point at the top of the curve has the coordinates (1,1). The dashed line is the diameter, and the dotted curve is the spinodal curve.

At a given temperature and pressure eqs. (4.7) and (4.8) must be solved simultaneously to determine the compositions of the two phases a and P that correspond to coexistence. At isobaric conditions, a plot of the composition of the two phases in equilibrium versus temperature yields a part of the equilibrium T, x-phase diagram. 

Figure 4.34 Phase diagram of water (a) P versus V (b) V versus T...

Figure 5.19 P versus T phase diagram for ethane (0.3) + propane (0.7) + water (excess) system with pseudo-retrograde phenomena.

Projecting the new phase transition points (Tm, Pi) and (7b, Pi) onto the phase (P versus T) diagram leads to points D and C and hence the line AD represents the variation of melting point (i.e. solid-liquid equilibria) with pressure for the substance whilst the line CB represents the variation in the boiling point with pressure for the liquid/gas equilibrium. 

On the phase diagram (Figure 23.3) the lines AD, BC and EF when extrapolated meet at a point labelled as the triple point, corresponding to one single specific temperature and one single specific pressure at which all three phases (solid, liquid and gas) will coexist and be equally stable (see Frame 50, section 50.4). This corresponds to the situation (at a specific pressure which we have labelled P ) where the curves of Gg, G and Gs versus temperature mutually intersect with one another. 

This is a further form of the Clapeyron Equation which gives the slope of the P versus T line (BC) for the liquid-vapour equilibrium in the phase diagram. 

These matters are well summarized pictorially in the phase diagram for water, Fig. 2.3.1 (not drawn to scale), which is a representative plot of pressure versus temperature. The three solid curves separate out three large regions within which T and P may be altered arbitrarily while maintaining... 

Hgurc 4.14 (a) A typical phase diagram for a poly (p-phenylene terephthala-mide)-sulfuric acid system, a solution that is used to make Kevlar fiber (after Kikuchi, 1982). (b) Viscosity versus polymer concentration in PPTA/HjSO solution. Note the sharp drop in viscosity at about 20% which corresponds to a transition between isotropic and nematic liquid crystal phase. 

FIGURE 11.13 Phase diagram plotted as particle density, >, versus salt concentralion for particle charge Z = 400 (a) particle diameter of 0.109 un, (b) particle diameter of 0.234 p.m, (c) particle diameter of 0.400 /am. The BCC—FCC phase boundaries are the same for the three cases, but the liquid-solid phases boundaries are pushed to lower densities as the particle size is increased. Taken from Shih et al. [48]. Reprinted by permission by El vier Science Publishing. 

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