Eduard E. Levin

Mechanochemically induced formation of amorphous phase at oxide nanocomposite interfaces

α-Fe2O3-Fe mixtures of different compositions ground in high energy ball mill were studied. The formation of amorphous iron-based magnetic phase was detected by means of Mossbauer spectroscopy and magnetic measurements. The amount of this phase increases with Fe/α-Fe2O3 ratio in starting mixtures increase. Its thermal stability was studied by means of magnetic and DCS measurements.

Moving crystal assembly for handling small bulk samples

The conventional zero-background holder technique has been adapted for handling small bulk samples by adding one-axis mobility to a single-crystal wafer using a Newport optical stage. Experiments showed that an a-plane (11{\overline 2}0) sapphire crystal with a surface-to-crystal-plane angle of ∼3° can be used as a zero-background holder. Such a crystal is a viable alternative to the commercial Rigaku product and shows better performance in the intermediate angle range (2θ = 60–110° for Cu Kα radiation). It has also been demonstrated that the proposed scheme of hardware stacking is operational.

Microstructure refinement in Cu-Fe alloy using high pressure torsion

The effect of high pressure torsion (HPT) on the microstructure evolution of Cu-Fe 36% wt alloy has been studied. The initial Cu-Fe alloy has a dendritic structure, the length of dendrites is up to 100 gm. As a result of HPT (20 anvil rotations at 400 ?C) the refinement of a- Fe dendrites occurs, and a microstructure with Fe inclusions with a size from 0.1 to 5 gm uniformly distributed in the copper matrix forms. Subsequent annealing at 700 ?C for 1 hour results in some coarsening of a-Fe particles, as compared to the state after HPT. However, the dendritic structure typical of the cast alloy does not recover; it remains dispersed with a size of a-Fe particles less than 20 gm. As a result of HPT the alloy microhardness increased from 1800 to 4000 MPa. The subsequent annealing at T = 700 ?C decreased the microhardness to 2700 MPa, but this value is 1.5 times higher than that in the initial as-cast state.

The formation of Fe–Ga–In nanocomposite particles using mechanochemical interaction of Fe with the Ga–In eutectic

Mechanochemical interaction of Fe powder with the liquid Ga–In eutectic in the Fe-rich concentration corner of the Fe–Ga–In phase diagram was studied and compared with binary Fe–Ga and Fe–In specimens. Slow formation of diluted solid solutions in the Fe–In system was confirmed. In the Fe–Ga system, the dominant concentrated A2 solid solution is formed with Heff = 236 kOe, accompanied by ordered D03 and L12 phases. The Fe–Ga–In system features a stationary equilibrium between the concentrated A2 phase and D03 in the iron matrix.