Narrow Results

In order to promote suitable material to be used in spintronics devices, this study purposes to evaluate the magnetic properties of the titanium and vanadium-doped zinc-blende ZnO from first-principles. The calculations of these properties are based on the Korringa–Kohn–Rostoker (KKR) method combined with the coherent potential approximation (CPA), using the local density approximation (LDA). We have calculated and discussed the density of states (DOSs) in the energy phase diagrams for different concentration values, of the dopants. We have also investigated the magnetic and half-metallic properties of this doped compound. Additionally, we showed the mechanism of the exchange coupling interaction. Finally, we estimated and studied the Curie temperature for different concentrations.

Using the first-principles calculations within the Korringa–Kohn–Rostoker (KKR) method combined with the coherent potential approximation (CPA), the structural, optical and magnetic properties of rare-earth nitride Ho${}_{0.95}$TM${}_{0.05}$N doped with transition metal (TM) atoms (Ti, V, Cr, Mn, Co and Ni) are investigated as a function the generalized gradient approximation and self-interaction correction (GGA–SIC) approximation. The optical properties are studied in detail by using ab-initio calculations. Using GGA–SIC we have showed that the bandgap value is in good agreement with the experimental value. Using GGA–SIC approximation for HoN, we have obtained a bandgap of 0.9 eV. Some of the dilute magnetic semiconductors (DMS) like Ho${}_{0.95}$TM${}_{0.05}$N under study exhibit a half-metallic behavior, which makes them suitable for spintronic applications. Moreover, the optical absorption spectra confirm the ferromagnetic stability based on the charge state of magnetic impurities.

The ab initio study of electronic, magnetic properties and Curie temperature of AlAs doped by single and double impurities is investigated using LDA–KKR–CPA method. It is shown that the Al substituted by V and/or Ti induces a half-metallic character and ferromagnetism in the system for different concentrations except co-doping by x=y=0.035. The stability of magnetism between the ferromagnetic and DLM states as well as the mechanism of exchange interaction are discussed. The density of states are plotted in the energy diagram for different concentrations of dopants. The co-doping with (V, Ti) increases Curie temperature in AlAs with respect to single substituant. The finding of this work confirms that the new compounds have a great potential for spintronic devices.