Single-Layer Composite Films

Fig. 58. Anomalous hysteresis loops in a single-layer TbFe film having a compositional gradient, measured by the Hall effect (top) and the Kerr magneto-optical effect (bottom). (After Chen and...

The principle application of XRF thin-film analysis is in the simultaneous determination of composition and thickness. The technique has been used for the routine analysis of single-layer films since 1977 and multiple-layer films since 1986. Two main sources of publications in the fields are the annual volumes of Advances in X-Ray Analysis by Plenum Press, New York, and the Journal of X-Ray Spectrometry by Heyden and Sons, London. Typical examples on the analysis of single-layer films and multiple-layer films are used to illustrate the capabilities of the technique. 

In multiple-layer thin films, it is possible that some of the elements may be present simultaneously in two or more layers. XRF analysis of this type of film can be complicated and cannot be made solely from their observed intensities. Additional information, such as the compositions or thickness of some of the layers is needed. The amount of addidonal non-XRF information required depends on the complexity of the film. For example, in the analysis of a FeMn/NiFe double-layer film, the additional information needed can be the composition or thickness of either the FeMn or NiFe layer. Using the composition or thickness of one of the film predetermined from a single-layer film deposited under identical condidons, XRF analysis of the FeMn/NiFe film was successfiil. ... 

Fig. 2.18. Kelvin probe force microscopy (KPFM) picture of the cross-section of a modulation doped Zni- Mg CtAl/ZnO film on a silicon substrate. The contact potential is given relative to pyrolytic graphite ( = 4.07 eV). The local variation of the contact potential is shown on the left side, while the chemical composition, determined by SIMS is displayed on the right side. Deposition parameters p = 0.2Pa, P = 75Wrf, Tsub = 300°C, single layer thickness dZno = dZni xMgxO Ai = 160 nm...

It is now well accepted that the passive film is not a single layer, but rather has a stratified structure. The inner layer plays the role of a barrier layer against corrosion and the outer layer plays the role of an exchange layer. The chemical composition is a... 

SEa (Single layer of composite film) SEr (Single layer of composite film)... 

It is also possible to characterize accurately the composition of new thin fihn materials using RBS. RBS analysis of the Sri xCaxCu02 materials demonstrates that the single-phase infinite-layer thin films have the same average composition as the multiphase targets from which they were prepared by laser ablation. These compositional analysis results demonstrate that PLD can be used to prepare readily a specific stoichiometry material even when the target is not single phase. 

Figure 21.5 The depth profiles of the composition ungraded and graded (layered by single electrode process) films prepared by using copper electrode.

H. Suzuki, Composite membrane having a single layer of an ultra thin film of cage shaped zeolite and process for production thereof. US patent 5.069.794. 

The effect of nanoparticles in composite films used for both the emitting layer (EL) and HTL in OLEDs was revealed by measuring the I-V characteristics of the devices made from different layers, such as a single pure EL diode (ITO/MEH-PPV/ Al, abbreviated as SMED), a double pure polymer diode (ITO/PEDOT/MEH-PPV/Al or PPMD), a double polymeric... 

It should be noted that the anodization constant ka for multi-layer compositions differs from that for a single tantalum film. This is because the anodization voltage for the Ta film on a dielectric substrate is 1.5 to 2 times higher than that in the case of A1 bottom layer. Relationships between current density, anodization duration and forming voltage at a constant scanning rate of voltage have been obtained. 

Single-layer and combined films can be produced without heating by compaction or rolling of powder polymer compositions followed by sintering in an oven. Combined film materials are mainly formed by pressing with heating. Because of low productivity and imperfect quality of films produced this way compaction is infrequently used in industry [3]. 

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