Monolayer amorphous

The first step of oxide-layer formation is oxygen adsorption (chemisorption). In the case of platinum, the process stops at this stage, and depending on the conditions, an incomplete or complete monolayer of adsorbed oxygen is present on the platinum surface. In the case of other metals, layer formation continues. When its thickness 5 has attained two to three atomic diameters, the layer is converted to an individual surface phase that is crystalline (more seldom, amorphous) and has properties analogous to those of the corresponding bulk oxides. 

MORPHOLOGICAL AJVD STRUCTURAL STUDIES OF CRYSTALLINE AND AMORPHOUS MONOLAYERS ON THE WATER SURFACE... 

Also the surface of hydrophilic SiO substrate was confirmed to be smooth and amorphous, based on morphological and ED studies, respectively. Therefore, the crystallographic study of the monolayer and the surface characteristics of the substrate indicate that the hydrophilic SiO substrate is suitable for the electron microscopic morphological and structural investigations on the monolayer on the water surface. Then, the monolayer was transferred onto the hydrophilic SiO substrate by the upward drawing method[3,15] at a transfer rate of 60 mm-min 1 at various TSps and pressures, except at the surface pressure of 0 mN-nr1. The monolayer at 0 mN-nr1 can be transferred only by a horizontal lifting methodf 16). 

Fig. 12. Schematic representation for the molecular aggregating process of (a) crystalline monolayer and (b) amorphous monolayer. 

It is, therefore, clearly concluded from Figures 9-11 that in the case of conventional fatty acids such as myristic, palmitic, stearic and so on, the crystalline or amorphous phase of monolayer completely depends on the relative magnitude of Tsp to Tm of the monolayer, being independent of the magnitude of surface pressure. The fatty acid monolayers do not show any pressure-induced crystallization during compression of the monolayer on the water surface. The crystalline and amorphous monolayers are schematically summarized in Figure 12. 

Infrared spectroscopic analyses on molecular conformation in crystalline and amorphous monolayers... 

Fig. 14. Surface area dependences of surface pressure and frequency maximum of the CH2 asymmetric band for (a) crystalline stearic acid monolayer and (b) amorphous myristic acid monolayer.

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