scholarly journals Electronic and Magnetic Properties of Li1.5Mn0.5As Alloys in the Cu2Sb Structure

2013 ◽  
Vol 702 ◽  
pp. 231-235 ◽  
Author(s):  
C.Y. Fong ◽  
Liam Damewood ◽  
L.H. Yang ◽  
C. Felser
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ab Initio ◽  
Lattice Constant ◽  
Magnetic Moments ◽  
The Other ◽  
Half Metallicity ◽  
Ionic Model ◽  
Half Metals ◽  
Ferromagnetic Metals

We investigated two formula-units of Li1.5Mn0.5As alloys, such as Li3MnAs2, in the Cu2Sb crystal structure using an ab-initio algorithm. By interchanging Mn with each Li located at different positions of the Li4As2unit cell, four separate alloys are formed. At the optimized lattice constant, two of these alloys are predicted to be ferromagnetic metals and the other two are half metals. The possibility of half metallicity in the first two is also explored. Both the modified Slater-Pauling-Kübler rule and the ionic model can characterize the magnetic moments of the half metals.

Magnetism and Half-Metallicity in (100) Surface of Inverse Heusler Mn2CoSb

2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
First Principles ◽  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
Surface States ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.

STABLE STRUCTURES, ELECTRIC AND MAGNETIC PROPERTIES OF NANOPARTICLES COn(n = 1-6) CLUSTERS: FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362007
Author(s):  
JUN LIU ◽  
SHENG-BIAO TAN ◽  
HUI-NING DONG
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
First Principles ◽  
Lower Energy ◽  
Magnetic Moments ◽  
Molecular Orbitals ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Ground State Structures ◽  
Stable Structures

The ground state geometric structures of the nanoparticles or clusters CO n(n = 1-6) were given based on the first-principles calculations. Then the magnetic properties of the clusters CO n(n = 1-6) and ( CO n)-2(n = 1-6) were calculated in system. Results show that their ground state structures are closely related to the numbers of O-ions. These clusters have no magnetic moments and half-metallicity if they are electroneutral. However, they have magnetic moments if they have positive or negative charges. The total magnetic moments of the clusters ( CO n)-2(n = 1-6, but n≠3) are all 2.0000 μB, and all their ions have contributions to the total magnetic moments. The main reason is that the molecular orbitals with lower energy filled with paired electrons and the molecular orbitals with higher energy are occupied by two electrons in parallel.

scholarly journals The crystal structure of the heusler alloys

1934 ◽  
Vol 144 (852) ◽  
pp. 340-359 ◽  
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Heusler Alloys ◽  
The Other ◽  
X Rays ◽  
Ferromagnetic Alloys ◽  
Suitable Heat Treatment ◽  
Copper Manganese ◽  
Ferro Magnetic

Beginning in the year 1898 Heusler discovered as a series of ferromagnetic alloys, the most important containing copper, manganese, and aluminium. They are characterized by remarkable magnetic properties, because although composed only of paramagnetic or diamagnetic elements, they become ferro-magnetic after suitable heat treatment. Various explanations of this property have been advanced, but it was usually considered to be due to the formation of a series of solid solutions of the type (CuMn) 3 Al, in which the proportions of copper and manganese may be varied within fairly wide limits. The Heusler alloys have been repeatedly investigated by means of X-rays. Young, using molybdenum radiation examined alloys of two different compositions. He found that one was face-centred cubic, while the other was a mixture of face-centred and body-centred cubic structures. The mixed alloy was the more magnetic.

FIRST PRINCIPLES STUDY OF ELECTRONIC STRUCTURE AND MAGNETIC PROPERTIES OF HALF-METALLIC FULL-HEUSLER ALLOYS Co2MnSi and Co2FeSi

2010 ◽  
Vol 24 (08) ◽  
pp. 967-978 ◽  
Author(s):  
JINGSHAN QI ◽  
HAILIN YU ◽  
XUEFAN JIANG ◽  
DANING SHI
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Lattice Parameters ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Half Metallic

We present a comprehensive investigation of the equilibrium structural, electronic and magnetic properties of C o2 MnSi and C o2 FeSi by density-functional theory (DFT) within the generalized gradient approximation (GGA) using the projected augmented wave (PAW) method. The on-site Coulomb interaction has also taken into account ( GGA +U) approach to unravel the correlation effects on the electronic structure. The change of the energy gap, "spin gap", Fermi energy level and magnetic moments with the lattice parameters is investigated. We found that the on-site correlation interaction in C o2 FeSi is stronger than in C o2 MnSi . So on-site electronic correlation is necessary for C o2 FeSi and the magnetic moments reproduce experimental results well by GGA +U. Further we also found that a moderate change of the lattice parameters does not change the half-metallic ferromagnet (HMF) behavior for both materials. Appearance of half-metallicity is consistent with the integral magnetic moments, which also agrees with the experiment measurements.

scholarly journals The Electronic, Magnetic, Half-Metallic and Mechanical Properties of the Equiatomic Quaternary Heusler Compounds FeRhCrSi and FePdCrSi: A First-Principles Study

2018 ◽  
Vol 8 (12) ◽  
pp. 2370 ◽  
Author(s):  
Liefeng Feng ◽  
Jiannan Ma ◽  
Yue Yang ◽  
Tingting Lin ◽  
Liying Wang
Keyword(s):  
First Principles ◽  
Mechanical Stability ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Half Metallicity ◽  
External Interference ◽  
Half Metals ◽  
Wide Range ◽  
Quaternary Heusler Alloys ◽  
Low Sensitivity

By using the first-principles method, the electronic structures and magnetism of equiatomic quaternary Heusler alloys FeRhCrSi and FePdCrSi were calculated. The results show that both FeRhCrSi and FePdCrSi compounds are ferrimagnets. Both compounds are half-metals and their half-metallicity can be maintained in a wide range of variation of the lattice constant under hydrostatic strain and c/a ratio range under tetragonal distortion, implying that they have low sensitivity to external interference. Furthermore, the total magnetic moments are integers, which are typical characteristics of half-metals. The calculated negative formation energy and cohesive energy indicate that these two alloys have good chemical stability. Furthermore, the value of the elastic constants and the various moduli indicate the mechanical stability of these two alloys. Thus, FeRhCrSi and FePdCrSi are likely to be synthesized in the experiment.

Theoretical study of structural, electronic and magnetic properties of equiatomic quaternary CoPdCrZ (Z = Si, Ge, P) Heusler alloys

2019 ◽  
Vol 33 (31) ◽  
pp. 1950389 ◽  
Author(s):  
Hafsa Arshad ◽  
M. Zafar ◽  
S. Ahmad ◽  
M. Rizwan ◽  
M. I. Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Full Potential ◽  
Type I ◽  
Augmented Plane Wave ◽  
Half Metals ◽  
Electronic And Magnetic Properties ◽  
Quaternary Heusler Alloys ◽  
Linearized Augmented Plane Wave

In this study, the structural, electronic and magnetic properties of Co-based equiatomic quaternary Heusler alloys (EQHA) CoPdCrZ (Z = Si, Ge, P) are investigated by full potential linearized augmented plane wave (FP-LAPW) method. Three different configurations are employed to find out the most stable structure by structural optimization process. The alloys CoPdCrSi and CoPdCrGe are found to be stable in Type-II structure while CoPdCrP is in Type-I. The calculated electronic and magnetic properties show that CoPdCrSi and CoPdCrGe are nearly half metals while CoPdCrP is a ferromagnetic alloy. By following the Slater–Pauling rule [Formula: see text], the total magnetic moments are calculated. The spin polarization and Curie temperature have also been calculated.

Ab initio determination and Rietveld refinement of the crystal structure of Ba7Cl2F12

1998 ◽  
Vol 13 (3) ◽  
pp. 152-156 ◽  
Author(s):  
B. Es-Sakhi ◽  
P. Gravereau ◽  
C. Fouassier
Keyword(s):  
Crystal Structure ◽  
Ab Initio ◽  
Rietveld Method ◽  
Heavy Atom ◽  
The Other ◽  
Halide Ions ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Heavy Atom Method ◽  
Trigonal Prisms

The structure of Ba7Cl2F12 has been determined ab initio from conventional X-ray powder diffraction data by the “heavy atom” method. The cell is hexagonal (space group P6¯, Z=1), with a=10.6373(2) Å and c=4.1724(2) Å. Refinement of 38 parameters by the Rietveld method, using 278 reflections, leads to cRwp=0.173, cRp=0.135, and RB=0.054. The structure has common characteristics with that of the other BaF2-rich fluorochloride, Ba12Cl5F19. In both phases Ba2+ ions lie in tricapped trigonal prisms formed by nine halide ions, and Cl− ions occupy the center of trigonal prisms of Ba2+ ions. F− ions are located in cationic tetrahedra or square pyramids.

Ab initio study of Cr substitution for Co in the Heusler alloy Co2CrAl: Half-metallicity and adjustable magnetic moments

2008 ◽  
Vol 403 (10-11) ◽  
pp. 1797-1802 ◽  
Author(s):  
Hongzhi Luo ◽  
Li Ma ◽  
Zhiyong Zhu ◽  
Guangheng Wu ◽  
Heyan Liu ◽  
...  
Keyword(s):  
Ab Initio ◽  
Heusler Alloy ◽  
Magnetic Moments ◽  
Ab Initio Study ◽  
Half Metallicity ◽  
Cr Substitution
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