Herringbone Diagrams

Figure 6 Slowness and group velocity diagrams for austenitic weld material herringbone grain orientation...

Phase transitions in two-dimensional layers often have very interesting and surprising features. The phase diagram of the multicomponent Widom-Rowhnson model with purely repulsive interactions contains a nontrivial phase where only one of the sublattices is preferentially occupied. Fluids and molecules adsorbed on substrate surfaces often have phase transitions at low temperatures where quantum effects have to be considered. Examples are molecular layers of H2, D2, N2 and CO molecules on graphite substrates. We review the path integral Monte Carlo (PIMC) approach to such phenomena, clarify certain experimentally observed anomalies in H2 and D2 layers, and give predictions for the order of the N2 herringbone transition. Dynamical quantum phenomena in fluids are analyzed via PIMC as well. Comparisons with the results of approximate analytical theories demonstrate the importance of the PIMC approach to phase transitions where quantum effects play a role. 

Figure 4.14. Phase diagram, coverage vs. temperature, of N2 physisorbed on graphite. Symbols used fluid without any positional or orientational order (F), reentrant fluid (RF), commensurate orientationally disordered solid (CD), commensurate herringbone ordered solid (HB), uniaxial incommensurate orientation-ally ordered (UlO) and disordered (UID) solid, triangular incommensurate orientationally ordered (lO) and disordered (ID) solid, second-layer liquid (2L), second-layer vapour (2V), second-layer fluid (2F), bilayer orientationally ordered (2SO) and disordered (2SD) solid. Solid lines are based on experimental results whereas the dashed lines are speculative. Adapted from Marx Wiechert, 1996.

Figure 35. Schematic phase diagram of the three-axis cubic model including the effect of dislocations to model the herringbone transition in floating-solid (incommensurate) phases (see Section III.E for details). The orientational and melting transitions of real N2 on graphite are expected to occur on a path crossing somewhere the bold solid lines BF and BE, respectively. (Adapted from Fig. 5 of Ref. 60.)...

Figure 4.21 Staggered herringbone mixer angle of the ridges with respect to the chan-(SHM). (a) Schematic diagram of one-and- nel, 0=45°, fte<0.01 [36]. (Adapted with a-halfcycles of the SHM. (b) Confocal micro- permission of The American Association for graphs of vertical cross sections of a channel, the Advancement of Science.) h = ll pm, w = 200 pm, a = 0.23, pw= 2/3w,...

Figure 3.2 Packing diagram of compound 12 showing the herringbone pattern...

Figure 10.3 (a) Schematic diagram of a 16-column microfluidic DNA synthesizer. The control lines, fluidic lines, herringbone mixers, and the square profiled binary tree and reactor columns are shown, (b) Close up schematic of the column array. The normal valve and the individually addressable inlet valve close fully when activated the sieve valve and compression valve of the reaction columns allow fluid flow while trapping the CPC beads. 

Figure 10. Crystal packing diagram for the high-temperature polymorph of a-6T illustrating the herringbone structure. From Ref. 39 (MRS).

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