The structural modification upon milling in an intermediate step precursor of the sol-gel method for BaFe12O19 hexaferrite BaM production is discussed. The milling of the precursor diminishes the powder particle size, leads to a more homogeneous matrix and induces a solid-state transformation, from γ-Fe2O3 to α-Fe2O3. The induced modifications of the precursors change the magnetic and structural properties of the final BaM hexaferrite compared to the BaM obtained from the non-milled precursor.

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Ceramic materials are widely studied for their high temperature structural applications. In many crystalline ceramics the range of solid solution decreases with temperature and thus precipitation of a second phase occurs. Thus, ceramics can be hardened by precipitation of second phases. However little is known regarding the effect of precipitation and nanocrystalline grain structure in the ductility of ceramic materials. On the other hand, oxide ceramics are under intense-investigation for their technological advantages in magnetization, dielectric response and chemical stability in such diverse uses as magnetic recording media, induction cores and microwave resonant circuits. This investigation has been undertaken to produce, characterize and measure the properties of ceramics that can be hardened by precipitation. The selected systems include Fe(1-x)O-Fe3 and MgO MgFe2O4. Mechanical milling is used to produce nanocrystalline ceramic oxides in the systems Fe(1-x)O-Fe3 and MgO-MgFe2O4 The mechanically alloyed powders are consolidated by means of spark plasma sintering (SPS) at temperatures ranging from 673 K to 1273 K and a pressure varying from 500 to 50 MPa in vacuum.

A new electrode material based on the Li 0?33 La 0?56 TiO 3 -polyaniline nanocomposite is reported. This material is prepared by in situ polymerisation of aniline in the presence of Li 0?33 La 0?56 TiO 3 nanoparticles. The nanocomposite and its precursors are characterised by X-ray diffraction, thermogravimetry, Fourier transform infrared, TEM, SEM, electrical conductivities and electrochemical measurements. The structural and electrochemistry study reveals the existence of relatively strong interactions between the conducting polymer and the oxide particles to assure good synergy in the transport process. The dc and ac electrical conductivities and diffusion coefficient measurements at room temperature indicate that the conductivity values are several orders of magnitude higher in the composite than in the oxide alone. This behaviour determines better reversibility for Li insertion in charge-discharge cycles compared to the pristine oxide and polymer when it is used as electrode of lithium batteries.