Real and simulated fractal aggregates

We have obtained interesting metallic fractal aggregates through an evaporation-condensation method. In order to interpret these results, computer simulation programs based on the DLA model have been developed, as well as methods to approximate the determination of the fractal dimension and another to compare two aggregates.     

Study of structural and electronic transport properties of Ce-doped LaMnO3

The structural and electronic transport properties of La_1−x Ce _x MnO₃ (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration up to 50% doping. The system La_0.5Ce_0.5MnO₃ also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition.     

On the determination of the nucleon-nucleon scattering parameters through final state interactions

The systematic errors introduced in the determination of the nucleon-nucleon scattering length from final state interaction spectra, due to the ommission of relevant processes in the ³He(π,α)2p reaction, are shown to be at least 0.2 fm.     

Final state interaction and direct features of the 9Be(τ, α)αα and 10B(d, α)αα reactions

Alpha-particle spectra and α-α correlations have been measured from the ⁹Be(τ, α)αα and ¹⁰B(d, α)αα reactions at several energies between 2.9 and 10.0 MeV. Significant difierences in the spectra from the reactions were observed at equal c.m. energies and momentum transfer values. However the continuous energy spectra have been successfully analyzed with two-body interactions as obtained from elastic α-α scattering, within a formalism adequate for a three-body state. DWBA fits have also been obtained for both reactions but they are satisfactory only for the ⁹Be(τ, α)⁸Be reaction.