Magnetic devices examples

Two examples of magnetic devices are discussed in the following sections. 

Magnetic properties are important in the function of electronic devices. An example is the use of yttrium iron garnet (YIG) in microwave devices. On applying an external magnetic field to a YIG disk, the input, say energy of one particular frequency selectively passes to the output. Thin films based of YIG within which magnetic waves can pass have proven to be useful. The use of lanthanides in magnetic devices as transducers is listed in Table 12.18. 

Donaldson [1988] also reports two examples where magnetic devices were installed in zinc phosphate spray systems where evidence was found for ... 

Materials that are used for example in modem catalysis, pharmaceuticals, electronics, optical and magnetic devices present a serious challenge to any theory which aims to give quantitative, chemically accurate analyas and pr ictions. Density Functional theory (DFT) [1-3] has proved to be a reliable tool in many sudi cases for which traditional advanced post Hartree-Fock (HF) methods of quantum chemistry and many-body physics are too computationally expensive or inapplicable yet [4,5], We review here our recent computational work using the DFT approach and analyse the methodological and techihcal problems encountered [6-15]. 

In this section we study the magnetic behavior of different types of iron clusters on Ag(lOO). We have chosen this example because from the fundamental point of view it is worthwhile to study how the modification of the local environment affects the magnetization. From the experimental point of view, supported clusters are easier to grow and characterize than free standing clusters. Besides, most of the applications for magnetic devices are based on supported systems. 

An imponant component of the complex metallizations for both semiconductor devices and magnetic media is the diffusion barrier, which is included to prevent interdiffiision between layers or diffusion from overlyii layers into the substrate. A good example is placement of a TiN barrier under an Al metallization. Figure 7a illustrates the results of an SNMSd high-resolution depth profile measurement of a TiN diffusion barrier inserted between the Al metallization and the Si substrate. The profile clearly exhibits an uneven distribution of Si in the Al metallization and has provided a clear, accurate measurement of the composition of the underlying TiN layer. Both measurements are difficult to accomplish by other means and dem-... 

In summary, the forte of SNMS is the measurement of accurate compositional depth profiles with high depth resolution through chemically complex thin-film structures. Current examples of systems amenable to SNMS are complex III-IV laser diode structures, semiconductor device metallizations, and magnetic read-write devices, as well as storage media. 

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