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In this study, the electronic structure and magnetic properties of novel half-metallic Ti2FeSi full-Heusler compound with CuHg2Ti-type structure were examined by density functional theory (DFT) calculations. The electronic band structures and density of states of the Ti2FeSi compound show the spin-up electrons are metallic, but the spin-down bands are semiconductor with a gap of 0.45 eV, and the spin-flip gap is of 0.43 eV. Fe atom shows only a small magnetic moment and its magnetic moment is antiparallel to that of Ti atoms, which is indicative of ferrimagnetism in Ti2FeSi compound. The Ti2FeSi Heusler compound has a magnetic moment of 2 μB at the equilibrium lattice constant a=5.997 Å. 相似文献
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Xiao-Ping WeiXian-Ru Hu Shi-Bing ChuGe-Yong Mao Lei-Bo HuTao Lei Jian-Bo Deng 《Physica B: Condensed Matter》2011,406(5):1139-1142
Using a state-of-the-art full-potential electronic structure method within the generalized gradient approximation (GGA), we study the electronic structure and magnetic properties of the Mn2CuSi full-Heusler alloy. Calculations show that CuHg2Ti-type structure alloy is a half-metallic ferrimagnet with the Fermi level (εF) being located within a tiny gap of the minority-spin density of states. The conduction electron at εF keeps a 100% spin polarization. A total spin moment, which is mainly due to the antiparallel configurations of the Mn partial moments, is −1.00μB for a wide range of equilibrium lattice parameters. Simultaneously, the small spin magnetic moments of Cu and Si atoms are antiparallel. The gap mainly originates from the hybridization of the d states of the two Mn atoms. Thus, Mn2CuSi may be the compound of choice for further experimental investigations. 相似文献
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Half-metallic ferrimagnetism in the Ti2CoAl Heusler compound 总被引:1,自引:0,他引:1
Eser BayarNazmiye Kervan Selçuk Kervan 《Journal of magnetism and magnetic materials》2011,323(23):2945-2948
Density functional calculations performed on the Ti2CoAl Heusler compound confirm it to be a half-metallic ferrimagnet with the spin-down energy gap of 0.49 eV. The Ti2CoAl Heusler compound has a magnetic moment of 2 μB at the equilibrium lattice constant a=6.14 Å. The Ti2CoAl Heusler compound is ferrimagnetic and maintains the half-metallic character having 100% polarization for lattice constants ranging between 5.85 and 6.44 Å. 相似文献
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Xiao-Ping WeiXian-Ru Hu Bin LiuYi Lei Hong DengMing-Kun Yang Jian-Bo Deng 《Journal of magnetism and magnetic materials》2011,323(12):1606-1610
The first-principle calculations within density functional theory are used to investigate the electronic structure and magnetism of the Mn2ZnGe Heusler alloy with CuHg2Ti-type structure. The half-metallic ferrimagnets (HMFs) in Mn2ZnGe are predicted. The energy gap lies in the minority-spin band for the Mn2ZnGe alloy. The calculated total spin magnetic moment is −2μB per unit cell for Mn2ZnGe alloy, the magnetic moments of Zn and Mn(B) are antiparallel to that of Mn(A), and we also found that the half-metallic properties of Mn2ZnGe are insensitive to the dependence of lattice within the wide range of 5.69 and 5.80 Å where exhibiting perfect 100% spin polarization at the Fermi energy. 相似文献
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Electronic and magnetic properties of diluted B1−xMnxN alloys are calculated by means of the full potential linearized augmented plane wave (FP-LAPW) method and the generalized gradient approximation (GGA). A half-metallic state is predicted for a composition of 6.25%. The spin majority being metallic and minority being semiconducting. We found a total magnetic moment of 2 μB (Bohr-magnetons) per supercell, in agreement with the half-metallic behaviour. The main contribution of the cell magnetic moment is localized at the transition metal site Mn, with a local moment of 1.24 μB. 相似文献
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A. Birsan 《Current Applied Physics》2014,14(11):1434-1436
The electronic structure and magnetic properties of Zr2CoAl bulk material were investigated within the Density Functional Theory (DFT) framework. The material, basically a complete spin polarized half-metallic ferromagnet in the ground state, crystallizes in the ordered full-Heusler inverse structure (Hg2CuTi-type structure). The energy band gap, localized in minority spin channel is 0.48 eV at equilibrium lattice parameter, 6.54 Å. The total magnetic moment calculated, equal to 2 μB/f.u., is an integral, in agreement with the Slater-Pauling curve for full-Heusler alloys. 相似文献
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The electronic structure and magnetic properties of the Heusler compound Co2ScP have been investigated by the generalized gradient approximation based on density functional theory. The results show that the ground state phase of the Co2ScP compound possesses AlCu2Mn-type crystal structure and exhibits half-metallic ferrimagnetism. The total spin moment is 2 μB at the equilibrium lattice constant a0=5.83 Å, which agrees with the Slater–Pauling rule. The spin-up electrons are metallic, but the spin-down bands are semiconductor with a gap of 0.55 eV, and the spin-flip gap is of 0.07 eV. 相似文献
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J.L. López W.A. Pacheco Serrano S.L. Pereira H.-D. Pfannes 《Hyperfine Interactions》1999,122(1-2):209-215
Mössbauer spectroscopy, magnetization and X-ray diffrraction measurements of the ternary compound Y(Fe0.95Mn0.05)2 prepared by melting were performed in order to investigate the effect of the substitution of Mn on the magnetic properties of YFe2. The experimental results show change of the lattice parameter. The magnetization and the Curie temperature decrease with substitution of Fe by Mn. 相似文献
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ABSTRACTThe inverse Heusler alloys such as Ti2CoSi, Mn2CoAl and Cr2ZnSi were studied in the framework of density functional theory using FP-LAPW linearised augmented plane wave method in order to determine the different physical properties such as structural, electronic, magnetic and thermoelectric. The generalised gradient approximation (GGA) was used to treat the exchange–correlation energy and the Beck-Johnson (mBJ) approach was used to calculate the electronic properties. In all studied compounds, the stable type Hg2CuTi was energetically more favourable than Cu2MnAl type structure. The results show that two compounds (Ti2CoSi and Mn2CoAl) are both ferromagnetic (FM) while Cr2ZnSi is antiferromagnetic (AFM). The compounds Ti2CoSi and Mn2CoAl have a total magnetic moment of 3 and 2?μB, respectively, whereas the Cr2ZnSi alloy has a total magnetic moment equals zero. The Ti2CoSi, Mn2CoAl and Cr2ZnSi compounds exhibit half-metallic (HM) character with 100% spin polarisation at the Fermi level. Finally, the semi-classical Boltzmann theory implicit in the BoltzTraP code was used to calculate the electronic transport coefficients such as thermal and electrical conductivity, the Seebeck coefficient and the factor of merit. 相似文献
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We propose and investigate the properties of a digital ferromagnetic heterostructure consisting of a delta-doped layer of Mn in Si, using ab initio electronic-structure methods. We find that (i) ferromagnetic order of the Mn layer is energetically favorable relative to antiferromagnetic, and (ii) the heterostructure is a two-dimensional half-metallic system. The metallic behavior is contributed by three majority-spin bands originating from hybridized Mn-d and nearest-neighbor Si-p states, and the corresponding carriers are responsible for the ferromagnetic order in the Mn layer. The minority-spin channel has a calculated semiconducting gap of 0.25 eV. The band lineup is found to be favorable for retaining the half-metal character to near the Curie temperature. This kind of heterostructure may be of special interest for integration into mature Si technologies for spintronic applications. 相似文献
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利用x射线衍射及磁测量手段研究了Ho2AlFe16-xMnx系列化合物的结构.结果表明,该系列化合物具有Th2Ni17型结构;随着x的增加,化合物的单胞体积呈现非线性的变化,结合磁测量结果分析认为,在化合物的磁相变点附近存在较大的正的本征磁致伸缩.在160—285K温度范围内对Ho2AlFe14Mn2化合物进行的变温x射线衍射研究表明,该化合物在其居里点附近(220—270K)具有负热膨胀性质,其平均热膨胀系数为-14×10-4/K.
关键词:
Ho2AlFe16-xMnx化合物
负热膨胀
本征磁致伸缩 相似文献
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Xiao-Ping Wei 《Journal of magnetism and magnetic materials》2010,322(20):3204-3207
We study magnetism properties and the electronic structure of a new Mn-based Heusler alloys Mn2CuGe using ab initio electronic structure calculations. We take into account both possible L 21 structures (CuHg2Ti and AlCu2Mn types). The CuHg2Ti-type structure is found to be energetically more favorable than the AlCu2Mn-type structure and exhibits half-metallic ferrimagnetism. Calculations show that their total spin moment is for a wide range of equilibrium lattice constants and magnetic moment mainly comes from the two Mn atoms, while the Cu atom is almost nonmagnetic. The small total moment comes from the antiparallel configurations of the Mn partial moments. And the CuHg2Ti-type Mn2CuGe alloy keeps a 100% of spin polarization at the Fermi level. Thus, the Mn2CuGe is the compound of choice for further experimental investigations. 相似文献
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Xingfeng Zhu Yaxu Wang Lu Wang Yafei Dai Chenglin Luo 《Journal of Physics and Chemistry of Solids》2014
We investigate the pressure and site disorder effects on the half-metallicity and magnetic properties of the full-Heusler alloy Co2FeSi using first-principles density functional theory within the GGA and GGA+U schemes. The calculated lattice constant, bulk modulus and total magnetic moments are in excellent agreement with recent experiments. The volume compression leads to a slight increase of the minority band gap, i.e., the half-metallic properties of Co2FeSi can maintain under pressure. The disorder calculations reveal that Fe–Co type disorder significantly destroys the half-metallic character and reduces the spin polarization of Co2FeSi while disorder between Fe and Si can maintain half-metallic properties. Our results also show that the Fe–Co type disorder leads to degradation of the magnetism while the Fe–Si type disorder affects hardly the magnetism as observed in Co2FeSi. 相似文献
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Guo Guanghua M. V. Eremin N. P. Kolmakova A. S. Lagutin R. Z. Levitin 《Physics of the Solid State》2002,44(11):2091-2094
The magnetic properties of a tetragonal intermetallic compound, namely, HoMn2Ge2, are investigated experimentally and theoretically. The experimental temperature dependences of the initial magnetic susceptibility and the lattice parameters are obtained in alternating and static magnetic fields. The magnetization curves are measured in strong magnetic fields up to 50 T. The parameters of the crystal field and Ho-Mn and Mn-Mn exchange interactions are determined, and the temperature dependence of the magnetic field of the phase transition from an antiferromagnetic phase to a ferromagnetic phase in a magnetic field aligned along the tetragonal axis is calculated. 相似文献
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A. E. Kar’kin V. I. Voronin T. V. D’yachkova N. I. Kadyrova A. P. Tyutyunik V. G. Zubkov Yu. G. Zainulin M. V. Sadovskii B. N. Goshchitskii 《JETP Letters》2001,73(10):570-572
The effect of disorder induced by neutron irradiation in a nuclear reactor (thermal neutron fluence 1×1019cm?2) on the superconducting transition temperature T c and the upper critical field H c2 of polycrystalline MgB2 samples was investigated. Despite the appreciable radiation-induced distortions (more than ten displacements per atom), the initial crystal structure (C32) was retained. The temperature T c decreased from 38 to 5 K upon irradiation and was practically completely restored after the subsequent annealing at a temperature of 70°C. A weak change in the dH c2/dT derivative upon irradiation is explained by the fact that the irradiated samples are described by the “pure” limit of the theory of disordered superconductors. The suppression of T c upon disordering may be due to the isotropization of the originally anisotropic (or multicomponent) superconducting gap or to a decrease in the density of electronic states at the Fermi level. 相似文献
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F. Ahmadian 《Solid State Communications》2011,151(24):1927-1931
The first-principle calculations based on spin-polarized density functional theory were performed to investigate the structural, electronic and magnetic properties of TiTe compound. The results showed that the ground state phase of TiTe is a non-magnetic NiAs structure and the zincblende (ZB) TiTe structure becomes stable at −5.2 GPa. It was predicted that the ZB structure is a half-metal ferromagnet with a magnetic moment of per formula unit for the equilibrium lattice parameter. The minority- spin and spin-flip gaps were calculated equal to 2.84 eV and 0.2 eV, respectively. In addition, the reasons for appearance of half-metallicity and magnetism in the ZB TiTe were discussed. It was noted that the half-metallicity characteristic exists within a wide range of lattice constant which makes the ZB TiTe an interesting material in the field of spintronics. 相似文献