Electrical properties higher oxides

Recently, much attention has focused on amorphous tantalum oxide (aTaOJ films for DRAM applications. This material has a higher FOM than SiO, with e23, Ebi4 MV/cm, FOM8.1 pC/cm2, and is of particular interest for embedded DRAM applications, for the reasons mentioned above in the context of aZTT films. State-of-the-art films are believed to have adequate electrical properties, at least for present... 

The metallic character of the cation-deficient partially oxidized tetracyano-platinate complexes is of considerable interest because of their unusual anisotropic electrical properties. The method used in the preparation of these compounds is a modification of the procedure used by Levy1 and gives a higher yield of pure product than the syntheses previously described in the literature2 5 (only the potassium compound has been reported to date). 

It also has a high melting point, 240°C. excellent electrical properties and higher clarity than any other polyolefin. Its weaknesses are low rigidity and solvent resistance sensitivity to oxidation and high permeability, which can sometimes be converted into a virtue. 

Cyanide complexes of platinum occur most commonly in the divalent state, although there has been increasing interest in the complexes formed with platinum in a higher oxidation state. Among the complexes most recently studied have been the mixed valent complexes where platinum cyanides in the divalent state are partially oxidized. These complexes form one-dimensional stacks with Pt-Pt interactions. In the solid state these materials show interesting electrical conductivity properties, and these compounds are discussed by Underhill in Chapter 60. In this section the preparative procedures and spectroscopy of the complexes will be covered, but for solid state properties the reader is referred to Chapter 60. 

The lanthanide higher oxides have not only peculiar thermodynamic properties, but also unique physical and chemical properties. The physical and chemical properties are presented as a macroscopic parameter, such as the electrical conductivity, the coefficient of expansion, and the conversion rate of a catalysis process. Due to the lack of knowledge of the wide range of non-stoichiometry of the oxygen-deficient fluorite-related homologous series of the lanthanide higher oxides, the macroscopically measured data of the physical and chemical properties are scattered, and therefore, based on the structural principle of the module ideas a deep understanding the relationship between the properties and structures is needed. 

Substoichiometric films were obtained for p(O2) < 30mPa at low substrate temperatures up to Ts = 180°C. For higher substrate temperatures, Zn desorption occurs and thus, Al-rich films with poor electrical properties were grown with A1 content up to 6%. At higher reactive gas partial pressure, constant dopant concentration is observed with cm = 1.8 —2.5 at.%. For p(O2) = 30 —35mPa, the films exhibit a low resistivity of < 1,500 pD cm. For Ts > 100°C, films reveal resistivity of p = 340 — 890 ifl cm. At higher reactive gas partial pressure, excess reactive gas causes the oxidization of dopants and thus AI2O3 incorporation. These films show poor conductivity. 

Interesting electrical properties are to be expected with the stepwise extension of this TT-system. The preparation of multilayered cyclophanes proved to be laborious [6] nevertheless new synthetic methods in transition metal chemistry of arenes have opened up a promising alternative approach via preparation of multidecker sandwich complexes (structure type D in Fig. 3). First row transition metals like chromium, iron and cobalt [51] form strong coordinative bonds with arenes when their oxidation state is low [48a] whereas second and third row elements like ruthenium, rhodium and iridium are strongly bonded towards arenes in higher oxidation states [48a, 51]. Sandwich complexes of cyclophanes can be divided into two groups ... 

---