Aluminium dielectric properties

Concerning the two-layer model, the thickness and properties of each layer depend on the nature of the electrolyte and the anodisation conditions. For the application, a permanent control of thickness and electrical properties is necessary. In the present chapter, electrochemical impedance spectroscopy (EIS) was used to study the film properties. The EIS measurements can provide accurate information on the dielectric properties and the thickness of the barrier layer [13-14]. The porous layer cannot be studied by impedance measurements because of the high conductivity of the electrolyte in the pores [15]. The total thickness of the aluminium oxide films was determined by scanning electron microscopy. The thickness of the single layers was then calculated. The information on the film properties was confirmed by electrical characterisation performed on metal/insulator/metal (MIM) structures. 

The above results showed that an aluminium oxide film with the best dielectric properties was prepared in neutral electrolyte of 0.01 M tartaric acid at low current densities and formation voltages < 30 V. 

Other subjects recently discussed include the photocoabsorption of carbon monoxide and oxygen on ZnO,664 the relative photoabsorption of oxygen and methane over ZnO,665 the photocatalytic properties of ZnO and MgO,66 the effect of irradiation on the dielectric properties of Ti02,667 the photoluminescence of an oxide layer on aluminium,668 the singlet-triplet splitting of the free A-exciton in ZnO,659 the properties of the photosensitive film of copper in iodine solution,580 and the photosensitivity of layers of CuCla and [Fe(ox)8]3-.681... 

Zientara D, Bucko MM, Lis J (2007) Dielectric properties of aluminium nitride-y-AlO materials. J Eur Ceram Soc 27 4051-4054... 

Manufacturers Comments Heat curing. Solvent-free. Aluminium oxide filler. High strength. High thermal conductivity. Excellent electrical and dielectric properties. Low viscosity version of Eccobond A 401. 

The use of metallized electrodes on certain polymers provides the capacitor with self-healing properties during manufacture and throughout its working life. If breakdown should occur at a fault in the dielectric layer, the local heating causes the deposited aluminium in the vicinity to evaporate, leaving an area bare of metal around the hole produced by the breakdown. 

The measured enthalpies of adsorption of alkanes into zeolites are very large, and can be calculated from this formula [13]. The dielectric constants for the open networks formed by the aluminium silicate frameworks of zeolites can be related to the known and measured dielectric and optical properties of bulk quartz. The calculation assiunes that the zeolite framework tessellates a hyperbolic surface as described in Chapter 2. The polarisabilities of different adsorbate alkanes are also known. When the calculations are carried out for a whole range of alkanes as adsorbate molecules and for different zeolites (with differing pore structure and size) the agreement between measured and predicted heats of adsorption is excellent (cf. Fig. 3.2). The results depend... 

The electrical properties of the film were comparable to that of silicon dioxide films. Apparently, the obtained barrier aluminium oxide film can be seen as an excellent gate dielectric for organic field-effect transistors on flexible substrates. 

Due to their good donor properties formamide and acetamide dissolve many ionic compounds7 94,96 g ch as alkali halides, various salts of copper, zinc, cadmium, aluminium, tin, lead, nickel, mercury and other acceptor compounds, such as FeCls or SbCls. The high dielectric constants allow considerable dissociation of the compounds ionized in the solutions. 

Bulut showed that using boron instead of aluminium as the central atom leads to [B(hfip)4] ionic liquids, which are compatible with the usual laboratory atmosphere for days [42]. This gain in stability is traded in by about 30-50°C higher melting points and higher viscosities. Nevertheless, other properties such as the dielectric behaviour or the solubility of gases should show a similarly exciting trend. 

---