Kiessig fringes

Fig. 2.56 Beating of Kiessig fringes observed using X-ray reflectivity from a PVP PS-PVP tri block copolymer film (fes = 0.48, Mv = 120 kg mol ) with two discrete thicknesses of 1935 and 2229 A (de Jeu et al. 1993). The difference in height results from island and hole formation at the free surface, and is equal to the bulk domain spacing.

In general, the oscillations observed in the reflectivity profile (the so-called Kiessig fringes) yield a characteristic thickness in the system under study. These may be thought of as interference fringes from scattering by the top and bottom... 

Figure 9.13 X-ray reflectivity data of the aluminium oxide/DIP multilayer with least-square fits at different temperatures, (a) By heating the sample the initially well-defined Kiessig fringes slowly degrade and the roughness of the DlP/alu-minium oxide and aluminium oxide/...

TABLE 2 The Monolayer Thickness and the Total Thickness of the P2,io Sample Obtained from the Kiessig Fringes (Column 1) and the Periodicity of the Electronic Density (Column 2) for the Sample Prepared Without Prepressure"... 

LBK Film (44 Monolayers) Fit from Kiessig Fringes Fit from Bragg Peak ... 

Thin films of PMMA-fo-PF8H2A were investigated with XR [55]. A typical result shown in Fig. 9a indicates rather rough interfaces (the Kiessig fringes... 

The changes in enthalpy that occur at the LCOT of a P( /-S-f>-nBMA) copolymer (Mw=85K) were measured using differential scanning calorimetry (DSC). The volume change of the transition was determined by specular x-ray reflectivity measurements of the copolyma as a function of temperature. From the Kiessig fringes in the reflectivity profile, the thickness of the sample can be determined very... 

Figure 3. X-ray reflectivity profiles as a function of kz at the temperatures indicated. The reflectivity profiles have been offset vertically for clarity. The oscillations in the data, the Kiessig fringes, characterize the sample thickness independent of the film density. The line through the data were calculated by a simple three layer model as described in the text.

The obtained layer thickness increase with increasing toluene content xo in the solvent mixture is given in Fig. 28a. Shown is the swelling behavior of three different samples with different (dry) thicknesses. The maximum thickness increase that can be identified in the Kiessig fringes amounts to a factor of 3.7. 

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