Textures of the films

Oriented In-Plane Texture. In this kind of film the properties (H and in the various in-plane directions (texture and nontexture directions) are different. The texture of the film can be supported by the texture of the substrate and the crystal lattice can be smaller in the texture direction than in the transverse direction. This can be the source for strain-induced magnetic anisotropy (magnetostriction). It is also found that the crystal is aligned in the texture direction (92). 

The crystallographic texture of the films was dependent on the Cd content. Up to 3 at.%, the films were (111) textured, while for higher Cd concentrations they became (200) textured. The crystal size (measured from electron microscopy) was of the order of some hundreds of nanometers (somewhat smaller for larger Cd content) but increased again to ca. 1 jim for maximum Cd content just before phase separation. 

When potentloseatic conditions were used, the working electrode was held at a potential of +0.7 V vs the Ag/Ag+ reference electrode. A smooth green film formed immediately on the surface of the working electrode. The current density was ca. 0.5 mA/cm. After ca. 30 minutes, the texture of the film became quite rough and globular in appearance with a powdery surface. After polymerization was halted, the film was removed from the electrode, washed repeatedly in fresh acetonitrile, and sent for chemical analysis. The dc electrical conductivity (4-probe) of a washed and dried film synthesized by the above procedure was 0.04 (ohm-cm). 

The dipping operation is repeated to build up multilayer films. The moving barrier maintains constant pressure and the dipping operation is automated with pressure measurement through microprocessor controls. By this process layered films are formed by alternate molecular orientations. This technique offers better control over order, film thickness and reproducibility of the response behaviour of the layers formed than traditional methods such as vacuum sublimation, spin coating, etc. Each layer consists of domains which provide a uniaxial texture of the films [185]. In order to make use of these layers as components in optical and electrooptic devices the size and orientation of the individual molecules or crystal axis of the domains of the individual layer should be adjusted with reference to the external reference system. 

Stresses also affect the orientation and texture of the film. This is shown in Figure 27.18, where the tensile or compressive stresses developed in the material... 

Fig. 11.6 Texture and surface profile of polycrystalline thin film of 8-Tp-BTBT (30 nm) observed by optical microscope and confocal laser microscope (upper left), and microscope textures of the films of 8-Tp-BTBT (upper right) and lO-BTBT-10 (bottom right) after heating at 150 °C for 5 min...

Electrodeposition is a well-known method to produce in situ metalhc coatings by the action of an electric current on a conductive material immersed in a solution containing a salt of the metal to be deposited. Moreover, by controlhng synthesis conditions, the electrochemical synthesis/deposition can be used to produce thin films of oxides and/or l droxides on conductive materials [12]. The composition, morphology and texture of the film coating can be controlled by tuning the experimental parameters such as the potential, current density, deposition time, and plating solution composition. In... 

Figure 11.35 Shows the x-ray diffraction spectra for an as-deposited nanograined Cu-Mo alloy film and the separation into Cu and Mo phases resulting from a 60 minute anneal at 600°C. Note the peak shift visible in the 211 peak for the as-deposited film compared to the alloy film. The 110 peak also shifted but the scale of the shift is too small to be visible on these axes. Note also the absence of either the Cu 111 or the Cu 200 peaks in the as-deposited film. The combination of shifted Mo bcc peaks and the absence of Cu peaks shows that a single phase alloy was created. The texture of the film can be observed in the much greater size of the 211 peak in the as deposited film compared to the normally-stronger 110 peak. After annealing the behavior is reversed. [29,30]...

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