N. Benkhettou

Half-Metallic Ferrimagnetism in theTi2YAl (Y = Fe, Ni) Heusler Alloys

Using density functional theory with the full-potential linearized augmented plane wave method, we study the structural, electronic and magnetic properties of Ti2FeAl and Ti2NiAl alloys with Hg2CuTi-type structure. These alloys are found to be half-metallic ferrimagnets. In addition, the total magnetic moments of Heusler alloys are Ti2YAl (Y = Fe, Ni) agree with the Slater-Pauling rule (Mtot = Ztot - 18) with respective gap energies of 0.56 eV and 0.44 eV in the spin down channel.

Electronic and elastic properties of Ba2HgSn and Ca2HgSn Rattling Heusler

Semiconductor electronic components are the active elements of integrated circuits, and they are at the origin of all advances in electronics. A new semiconductor class consists in Rattling Heusler. The purpose of this work is to study the structural, electronic and elastic properties of X2HgSn (X = Ba, Ca) Heusler alloys by using the first-principle projector augmented wave potential within the generalized gradient approximation. Our calculations show that these compounds are all semiconductor and are ductile manner.

The Study of Dielectric Properties of Some Ionic Liquids Based on Imidazolium by Dielectric Spectroscopy and Data Mining.

Abstract Ionic liquids (ILs) are liquid salts of differentiating to all molten salts with temperature below 100° C (arbitrarily set with reference to the boiling point of water), but a large number of them are liquids at room temperature. The properties of ionic liquids such as their wide field of electro activity, their high conductivity, and high thermal stability have made them new prime candidates in searching for a new energy systems (photovoltaic cell, battery, solar concentrator ...). The present work objective is to study the physicochemical properties of some ionic liquids based on imidazolium ([BMIM]+ [BF4]-, [BMIM]+[PF6]-, [HMIM]+ [Br] -,[BMIM]+ [Br]−) and more particularly the dielectric properties. We performed measurements by dielectric spectroscopy to see the influence of the size of the anion and the length of the alkyl chain of the cation on the conductivity of ionic liquids at different temperatures. We made also theoretical study by using data mining techniques such as the analytical method principal components (PCA), that help us to study the relationships between variables (σ RT (S / m), Tg (K) lnσ∞ (S / m), B, T0 (K), m) and their relation with ionic liquids structure.