Fine-particle metal aluminates,$MAl_20_4$ where $M = Mg$, $Ca$, $Sr$, $Ba$, $Mn$, $Co$, $Ni$, $Cu$ and $Zn$ as well as $3CaO . Al_2O_3$ $(C_3A)$, $CaAl_{12}O_{19}$ $(CA_6)$ and $MgCeAl_{11}O_{19}$ have been prepared by the combustion of mixtures of the respective metal nitrates (oxidizers) and urea or carbohydrazide (fuels) at 500 or $350^0c$ respectively, over a time of 5min. The solid combustion products were identified by their characteristic X-ray powder diffraction patterns. The fine-particle nature of these metal aluminates was investigated using SEM, TEM, particle size analysis and surface area measurements. The surface areas of the as-prepared metal aluminates using carbohydrazide fuel were higher (45 to 85 $m^2g^{-1}$) compared with urea (1 to 20 $m^2g^{-1}$).

Combustion synthesis of fine-particle metal aluminates

https://core.ac.uk/download/pdf/11453214.pdf

Bulk and electrochemical properties of BiVO4

https://oatao.univ-toulouse.fr/2428/1/mauvernay_2428.pdf

Elaboration and characterization of Fe1–xO thin films sputter deposited from magnetite target

Strong metal support interaction with supported group VIII metals is associated with the phase transformation of the support employed. The reduced uptake of hydrogen and the enhanced reactivity in CO hydrogenation in these systems are associated with the geometrical dispersion of the metal species, which is identified to have arisen from the formation of a ternary oxide phase and its subsequent reorganization under high temperature reduction conditions. XPS experimental evidence is provided for this postulate.

Strong metal support interaction state in the Fe/TiO2 system- an XPS study

The aim of this thesis is to employ computer simulation techniques to study the surface and grain boundary properties of a range of oxides. C hapter 1 provides an introduction to the current state of experimental and simulation techniques in determ ining the properties of surfaces and grain boundaries in oxides. The two following chapters outline the theoretical m ethods employed in atom istic simula­ tion and described the potential models used for the calculations presented in this thesis. The rem ainder of this thesis presents the calculated results. In chapter 4 the energies of the low index surfaces of a range of oxides are considered. These in­ clude the surfaces of wiistite (FeO), rutile (T i0 2), spinel (MgAl20 4), m agnetite (Fe30 4) and forsterite (Mg2S i0 4). The results establish the im portance of surface relaxation and its effects on surface structure. Rearrangement of the cation distri­ bution at the surface of spinel is considered. Predicted equilibrium morphologies based on Wulff’s theorem are employed as a means of testing the simulation results by comparing them with experimental crystals. The structure, energies and formation energies of defects a t the surfaces of hem atite are discussed in chapter 5. The energies of cation and anion vacancies close to two of the low index surfaces of hem atite have been calculated. In addi­ tion isovalent im purity segregation to all of the low index surfaces of hem atite is considered. In chapter 6 the structures of the low index m irror twins in hem atite are discussed. Minimum energy configurations for each twin are obtained. Both the vacancy formation energies and the isovalent segregation energies are presented for the basal and rhombohedral twins.

C. N. R. Rao

Papers

Advances in solid state chemistry ; proceedings of the INSA Golden Jubilee Symposium on Solid State Chemistry, New Delhi, December 4-6, 1985