E. Şaşıoğlu

Slater-Pauling behavior in LiMgPdSn-type multifunctional quaternary Heusler materials: Half-metallicity, spin-gapless and magnetic semiconductors

We employ ab-initio electronic structure calculations to study 60 LiMgPdSn-type (also known as LiMgPdSb-type) quaternary Heusler compounds. All compounds obey the Slater-Pauling rule with diverse electronic and magnetic properties. 41 compounds are found to be half-metals, 8 spin-gapless semiconductors, and 9 semiconductors. CoVTiAl and CrVTiAl compounds are identified as ferromagnetic and antiferromagnetic semiconductors, respectively, with large energy gaps in both spin directions. All magnetic compounds are expected to have high Curie temperatures making them suitable for spintronics/magnetoelectronics applications.

Search for spin gapless semiconductors: The case of inverse Heusler compounds

We employ ab-initio electronic structure calculations to search for spin gapless semiconductors among the inverse Heusler compounds. The occurrence of this property is not accompanied by a general rule and results are materials specific. The six compounds identified show semiconducting behavior concerning the spin-down band structure and in the spin-up band structure the valence and conduction bands touch each other leading to 100% spin-polarized carriers. Moreover, these six compounds should exhibit also high Curie temperatures and thus are suitable for spintronics applications.

Effective Coulomb interaction in transition metals from constrained random-phase approximation

The effective on-site Coulomb interaction (Hubbard

Influence of mixing the low-valent transition metal atoms (Y, Y*=Cr, Mn, Fe) on the properties of the quaternary Co2[Y1−xYx*]Z(Z=Al, Ga, Si, Ge, or Sn) Heusler compounds

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Doping and disorder in theCo2MnAlandCo2MnGahalf-metallic Heusler alloys

) between localized \textit{d} electrons in 3\textit{d}, 4\textit{d}, and 5\textit{d} transition metals is calculated employing a new parameter-free realization of the constrained random-phase approximation using Wannier functions within the full-potential linearized augmented-plane-wave method. The

A proposal for an alternative class of spin filter materials: Hybridization-induced high-TC ferromagnetic semiconductors CoVXAl (X = Ti, Zr, Hf)

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Magnetic phase transition in half-metallic CoMnSb and NiMnSb semi-Heusler alloys upon Cu doping: First-principles calculations

values lie between 1.5 and 5.7 eV and depend on the crystal structure, spin polarization, \textit{d} electron number, and \textit{d} orbital filling. On the basis of the calculated

Conditions for spin-gapless semiconducting behavior in Mn2CoAl inverse Heusler compound

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Ab initio calculation of the effective on-site Coulomb interaction parameters for half-metallic magnets

parameters, we discuss the strength of the electronic correlations and the instability of the paramagnetic state towards the ferromagnetic one for 3\textit{d} metals.

Variation of the magnetic properties of Ni2MnGa Heusler alloy upon tetragonalization: a first-principles study

We complement our study on the doping and disorder in Co2MnZ compounds [I. Galanakis, K. Ozdogan, B. Aktas, and E. Şasioglu, Appl. Phys. Lett. 89, 042502 (2006) and K. Ozdogan, E. Şasioglu, B. Aktas, and I. Galanakis, Phys. Rev. B 74, 172412 (2006)] to cover also the quaternary Co2[Y1−xYx∗]Z compounds with the lower-valent transition metals Y, Y∗ being Cr, Mn, or Fe and the sp atom Z being one of Al, Ga, Si, Ge, and Sn. This study gives a global overview of the magnetic and electronic properties of these compounds since we vary both Y and Z elements. Our results suggest that for realistic applications the most appropriate compounds are the ones belonging to the families Co2[Mn1−xCrx]Z with x>0.5 irrespectively of the nature of the sp atoms since they combine high values of majority density of states at the Fermi level due to the presence of Cr, and half-metallicity with large band gaps. On the other hand, the presence of Fe considerably lowers the majority density of states at the Fermi level and when com...