Heusler Alloys (heusler + alloy)

Distribution by Scientific Domains


Selected Abstracts


Electronic states in Cu2MnX (X = Al, In and Sn) Heusler alloy studied by XMCD and multiple scattering calculations

JOURNAL OF SYNCHROTRON RADIATION, Issue 2 2001
Shigeaki Uemura
X-ray magnetic circular dichroism (XMCD) has been measured at Mn and Cu K-edge in Cu2MnX (X = Al, In, and Sn) Heusler alloy. The Mn K -edge spectrum shows a dispersion-type profile and the Cu K -edge resembles the Mn spectrum, which suggests that polarization of the p unoccupied bands originates commonly in Mn 3d states. To reproduce the observed spectrum by full multiple scattering calculations, Madelung potential has been taken into account. Charge redistribution is an important factor for the electronic structure in Cu2MnX Heusler alloy. [source]


Electronic structure, chemical bonding, and finite-temperature magnetic properties of full Heusler alloys

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 1 2006
Yasemin Kurtulus
Abstract The electronic structure, chemical bonding, and magnetic properties of 15 full Heusler alloys X2MnZ have been studied on the basis of density-functional theory using the TB-LMTO-ASA approach and the local-density (LDA), as well as the generalized-gradient approximation (GGA). Correlations between the chemical bondings derived from crystal orbital Hamilton population (COHP) analysis and magnetic phenomena are obvious, and different mechanisms leading to spin polarization and ferromagnetism are derived. As long as a magnetically active metal atom X is present, antibonding XX and XMn interactions at the Fermi level drive the systems into the ferromagnetic ground state; only if X is nonmagnetic (such as in Cu2MnZ), antibonding MnMn interactions arise, which again lead to ferromagnetism. Finite-temperature effects (Curie temperatures) are analyzed using a mean-field description, and a surprisingly simple (or, trivial) relationship between structural properties (MnMn interatomic distances) and TC is found, being of semiquantitative use for the prediction of the latter. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 90,102, 2006 [source]


Ferrimagnetism and antiferro- magnetism in half-metallic Heusler alloys

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2008
Iosif Galanakis
Abstract Half-metallic Heusler alloys are among the most promising materials for future applications in spintronic devices. Although most Heusler alloys are ferromagnets, ferrimagnetic or antiferromagnetic (also called fully-compensated ferrimagnetic) alloys would be more desirable for applications due to the lower stray fields. Ferrimagnetism can be either found in perfect Heusler compounds or achieved through the creation of defects in ferromagnetic Heusler alloys. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


First-principles calculations of structural, elastic and electronic properties of Ni2MnZ (Z = Al, Ga and In) Heusler alloys

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2009
H. Rached
Abstract We have performed ab-initio density-functional theory self-consistent calculations using the full-potential linear muffin-tin orbital method within local spin-density approximation to study the electronic and magnetic properties of Ni2MnZ (Z = Al, Ga and In) in L21 structure. The magnetic phase stability is determined from the total energy calculations for both the nonmagnetic (NM) and magnetic (M) phases. The theoretical calculations clearly indicate that at both ambient and high pressures, the magnetic phase is more stable than the nonmagnetic phase. The elastic constants at equilibrium are also determined. We derived the bulk and shear moduli, Young's modulus, and Poisson's ratio. The Debye temperature of Ni2MnZ was estimated from the average sound velocity. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


The way composition affects martensitic transformation temperatures of Ni,Mn,Ga Heusler alloys

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2007
X. Q. Chen
Abstract A systematic substitution of Ge, Si, C and Co for Ga in the non-stoichiometric Ni,Mn,Ga alloys was performed. The relationship between the compositions of different elements including Ni, Mn, Ga, Ge, Si, C, Co, In and martensitic transformation temperature (Ms) was studied in detail for the present alloys together with data collected from a variety of sources. It is found that Ms is a sensitive parameter to the composition. The size factor and electron concentration are usually thought to be the way the composition influences Ms in the Ni,Mn,Ga alloys. Here, analyzing by linear regression, the electron density maybe a most appropriate parameter to describe the way the composition influences Ms when compared with size factor and electron concentration. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]