Anisotropy films

Multiple patterned array areas were formed on the same Co -Pt perpendicnlar anisotropy film to evaluate the DC remanence curve by counting the nnmber of reversed dots with changing applied magnetic field. The Co-Pt film thickness is 15 nm. 

Anisotropy, film properties (film formation) Properties that differ in different directions in the plane of the film. Often due to anisotropy in the direction of the flux of depositing material or anisotropy in ion bombardment during deposition. 

In most cases, the injection molding conditions significantly affect the morphology and subsequently the bulk mechanical properties of the product. This effect is more pronounced when polymer blends or composites are used where the extent of dispersion and orientation of the disperse phases or reinforcements would affect the final property of the molding. In film insert moldings, it is important to ensure that the film is firmly attached to the substrate. Hence, the distribution of the disperse phases (Acrylonitrile-butadiene-styrene in polycarbonate) at the interface is investigated to establish correlations between phase anisotropy, film-substrate adhesion and bulk mechanical properties. 

Barnik M I, Kozenkov V M, Shtykov N N, Palto S P and Yudin S G 1989 Photoinduoed optioal anisotropy in Langmuir-Blodgett films J. Mol. Electron. 5 53-6... 

Ogawa K, Yonehara FI, Sho]i T, Kinoshita S, Maekawa E, Nakahara FI and Fukuda K 1989 Inplane anisotropy in Langmuir-Blodgett films of a oopper phthalooyanine derivative Thin Solid Films 178 439-43... 

Wetzel, R., Zirwer, D., Becker, M. Optical anisotropy of oriented deoxyribonucleic acid films of diffi-rcrit water content. Biopolymers 8 (1969) 391-401... 

In the case of Co—Cr having perpendicular anisotropy there is, in principle, a competition between the uniaxial anisotropy of a hexagonal stmcture and the demagnetizing energy of the thin film. In the case of magnetically separated Co—Cr columns (particulate morphology) then also the shape anisotropy contributes to the perpendicular anisotropy. 

The first paper about NiFe layers evaporated under an angle was pubHshed in the early 1960s (40). The films prepared this way are often called obHque-incidence or angle-of-incidence films. It was found that these kinds of films show an anisotropy whose strength depends on the angle of incidence of the atoms (a/ during deposition (Fig. 15). If is between 0 and 65 the anisotropy Hes parallel to the film plane and perpendicular to the incidence plane. 

Coercivity of Thin-Film Media. The coercivity ia a magnetic material is an important parameter for appHcations but it is difficult to understand its physical background. It can be varied from nearly zero to more than 2000 kA/m ia a variety of materials. For thin-film recording media, values of more than 250 kA / m have been reported. First of all the coercivity is an extrinsic parameter and is strongly iafluenced by the microstmctural properties of the layer such as crystal size and shape, composition, and texture. These properties are directly related to the preparation conditions. Material choice and chemical inborn ogeneties are responsible for the Af of a material and this is also an influencing parameter of the final In crystalline material, the crystalline anisotropy field plays an important role. It is difficult to discriminate between all these parameters and to understand the coercivity origin ia the different thin-film materials ia detail. 

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). 

Cobalt—chromium films (20 at. % Cr) exhibiting strong perpendicular anisotropy, ie, hexagonal i -axis normal to the substrate surface, have been studied (53). Fifty nanometer films are composed of columnar crystaUites and the domain size was found to be a few stmctural columns in diameter. Magnetization reversal was shown to occur by domain rotation in thick films. Thinner (ca 10-nm thick) films do not show the columnar crystaUite... 

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