Oxygen-to-metal ratio

Oxygen-to-metal ratio in the range 1.38-1.43 is accommodated by change in stacking sequence. 

Oxygen-to-metal ratio varies between 1.9 and 2.0 in these systems with no apparent point defects. 

In transition mode, the oxygen to metal ratio on the substrate is a continuous function of the oxygen partial pressure. It is, therefore, possible to control the stoichiometry of film and thus to optimize doping, morphology, and phase composition. 

The higher oxides where the oxygen to metal ratio x in the oxides is in the range of 1.5 to 2.0 are observed for cerium, praseodymium and terbium. These oxides exhibit fluorite-typed dioxides, which do not necessary mean x = 2.0 but usually the x value is slightly smaller than 2.0. Again, the composition of these oxides depends on the temperature, oxygen potential and physical state, besides their history of preparation and treatment [8-11]. 

A huge amount of research has been done on the solid compounds of transuranium elements. In this section, fundamental properties of oxide and some compounds of the transuranium elements are briefly overviewed. The oxygen to metal ratio (O/M ratio) is one of the important parameters to understand the solid-state behavior of these oxides. The fluorite-structure dioxide is well studied in the research of mixed oxide (MOX) nuclear fuels. O Table 18.14 gives fundamental properties of transuranium oxides (Morss 1991). Neptunium... 

All samples doped with LiCFjSOa, ether oxygen to metal ratio 25 1. % Yield was cdculated with respect to PMMA. 

OXALOHYDROXAMIC ACID AS A REDUCTOMETRIC TITRANT FOR THE DETERMINATION OF OXYGEN TO METAL RATIO IN NUCLEAR FUEL... 

The oxygen to metal ratio (O/M) is an important parameter governing many properties of the uranium oxide fuels. The (O/M) also affects fuel properties such as thermal conductivity and melting point. Diffusion coefficients and vapour pressures have also been reported to change by 3 or more orders of magnitude for a minor change of 0.02 in the (O/M) near the value of 2.00. Therefore, knowledge of O/M of the mixed oxide fuel is very essential. 

Various O/M measurement techniques have been employed and used over the past several years with varying degree of success. The method for O/M fuel pellets at the fabrication plant should be simple, rapid and accurate. A numbers of wet chemical methods for determining oxygen to metal ratio in uranium oxide have been reported in literature. All methods require specific temperature condition, sample pretreatment steps and also sophisticated instruments. 

To test the validity of the proposed method the oxygen to metal ratio was determined by the proposed method and by earlier reported method in the same lunnium oxide sample. The results are presented in Table 1 [A] and Table 1[B]. A value of 2.665 for the O/U ratio with a standard deviation of 0.0012 was obtained by the proposed method whereas a value of 2.666 with a standard deviation of 0.0013 was obtained by earlier reported method. Schaefer and Hibbits" reported that the expected value is 2.667. Our result is close to the expected value. 

Table 1[A] Determination of Oxygen to Metal Ratio in Uranium Oxide Proposed Method...

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