Preparation of nanostructured dysprosium titanate and study of its properties

Dysprosium titanate with an equimolar ratio of the oxides included in it was obtained by the plasma-chemical method from previously prepared mixed solutions of salt nitrates. The separation of the solid phase from the gas-vapor stream leaving the plasma-chemical reactor was carried out in vortex dust collectors. In all batches of the product, particles of the same morphological set were obtained, with a predominance of hollow spheres with an average size of 200 nm with crystallites of 10-60 nm in size included in them. Uniaxial pressing and subsequent grinding in a planetary mill, as well as electro-pulse dispersion, do not allow obtaining powders of the required dispersion and purity. To ensure close packing during pressing and sintering of powders, the destruction of gas-filled hollow spherical particles is required. For the destruction of spheres, methods have been developed for obtaining particles of the desired morphology directly in a plasma-chemical reactor, for example, a method for “explosive” dispersion of a powder in the process of plasma-chemical synthesis with the introduction of ammonium nitrate into the initial solution. The results of studies of the morphology, granulometric and phase composition of the obtained dysprosium titanate are presented.

Microwave-assisted dissolution of highly refractory dysprosium-titanate (Dy2TiO5) followed by chemical characterization for major and trace elements using ICP-MS, UV-visible spectroscopy and conventional methods

Dysprosium-titanate (Dy2TiO5), being highly refractory in nature, its dissolution using conventional (hot-plate and fusion) methods is very difficult. Hence, for quantitative dissolution, a microwave method has been developed. The instrumental parameters and amount of acids has been optimized. Studies have been carried out for precise and accurate estimation of major elements such as Dy, Ti, and Mo. An anion exchange column has been used to separate Mo, Dy and Ti. Analysis of these elements has been carried out using ICP-MS, UV-visible spectroscopy, and gravimetric methods. In the developed method, precipitation of molybdenum and dysprosium has been done using α-benzoine oxime, and oxalic acid respectively. These precipitates have been converted into their respective oxide form. The purities of these oxides (Dy2O3and MoO3) have been determined using ICP-MS. The method has been validated using synthetic samples where it is found that accuracy of Dy and Mo is >99% and precision is <1 (%RSD). The titanium has been determined using UV-visible spectroscopy with accuracy >98% and precision <2 (%RSD).

Pressureless Sintering of B4C Neutron Absorbing Material with Nano-Sized Rare-Earth Compounds Addition

The processing of boron carbide by pressureless sintering with nano-sized rare-earth compounds additives to obtain dense pellets for use as neutron absorber in fast breeder reactors is investigated. The effect of dysprosium aluminum garnet (DAG) and dysprosium titanate nanopowders on density and mechanical properties was studied. The addition of DAG and dysprosium titanate nanopowders was found to be beneficial in the densification of B4C powders. B4C with 5 wt. % of DAG or dysprosium titanate nanopowders, exhibiting bulk density of 2.14g/cm3 and 2.35 g/cm3, could be prepared by pressureless heating at 2120°C and 2160°C.