Exchange Splitting Research Articles

High-throughput computational discovery of In2Mn2O7 as a high Curie temperature ferromagnetic semiconductor for spintronics

Materials combining strong ferromagnetism and good semiconducting properties are highly desirable for spintronic applications (e.g., in spin-filtering devices). In this work, we conduct a search for concentrated ferromagnetic semiconductors through high-throughput computational screening. Our screening reveals the limited availability of semiconductors combining ferromagnetism and a low effective mass. We identify the manganese pyrochlore oxide In2Mn2O7 as especially promising for spin transport as it combines low electron effective mass (0.29 m0), a large exchange splitting of the conduction band (1.1 eV), stability in air, and a Curie temperature (about 130 K) among the highest of concentrated ferromagnetic semiconductors. We rationalise the high performance of In2Mn2O7 by the unique combination of a pyrochlore lattice favouring ferromagnetism with an adequate alignment of O–2p, Mn–3d, and In–5s forming a dispersive conduction band while enhancing the Curie temperature.

Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2

An ideal Weyl semimetal with a single pair of Weyl points (WPs) may be generated by splitting a single Dirac point (DP) through the breaking of time-reversal symmetry by magnetic order. However, most known Dirac semimetals possess a pair of DPs along an axis that is protected by crystalline symmetry. Here, we demonstrate that a single pair of WPs may also be generated from a pair of DPs. Using first-principles band structure calculations, we show that inducing ferromagnetism in the AFM Dirac semimetal EuCd2As2 generates a single pair of WPs due to its half-metallic nature. Analysis with a low-energy effective Hamiltonian shows that this ideal Weyl semimetal is obtained in EuCd2As2 because the DPs are very close to the zone center and the ferromagnetic exchange splitting is large enough to push one pair of WPs to merge and annihilate at Gamma while the other pair survives. Furthermore, we predict that alloying with Ba at the Eu site can stabilize the ferromagnetic configuration and generate a single pair of Weyl points without application of a magnetic field.

Proximity-induced exchange and spin-orbit effects in graphene on Ni and Co

The induced-proximity effects of nearly commensurate lattice structure of a graphene layer on Ni(111) and Co(0001) substrates in the AC stacking configuration are addressed through an analytical tight-binding approach within the Slater-Koster method. A minimal Hamiltonian is constructed by considering the hybridizations of the magnetic $3d$-orbitals of Ni(Co) atoms with the $p_z$-orbitals of graphene, in addition to the atomic spin-orbit coupling and the magnetization of the Ni(Co) atoms. A low-energy effective Hamiltonian for graphene/Ni(Co) describing the perturbed $\pi$-bands in the vicinity of the Dirac points is derived which enable us to get further insight on the physical nature of the induced-effective couplings to the graphene layer. It is shown that a magneto-spin-orbit type effect may emerge through two competing mechanisms simultaneously present, namely the proximity induced exchange and Rashba spin-orbit interaction. Such effects results in giant exchange splittings and robust Rashba spin-orbit coupling transferred to the graphene layer in agreement with recent density functional theory calculations and experimental observations. We further analyze the physical conditions for the appearance of intact Dirac cones in the minority spin bands as observed by recent photoemission measurements with spin resolution.

Dirac Electron Behavior for Spin-Up Electrons in Strongly Interacting Graphene on Ferromagnetic Mn5Ge3.

An elegant approach for the synthesis of graphene on the strong ferromagnetic (FM) material Mn5Ge3 is proposed via intercalation of Mn in the graphene-Ge(111) interface. According to the density functional theory calculations, graphene in this strongly interacting system demonstrates the large exchange splitting of the graphene-derived π band. In this case, only spin-up electrons in graphene preserve the Dirac-electron-like character in the vicinity of the Fermi level and the K point, whereas such behavior is not detected for the spin-down electrons. This unique feature of the studied gr-FM-Mn5Ge3 interface that can be prepared on the semiconducting Ge can lead to its application in spintronics.

Optical orientation and alignment of excitons in direct and indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment

The spin structure and spin dynamics of excitons in an ensemble of (In,Al)As/AlAs quantum dots (QDs) with type-I band alignment, containing both direct and indirect band gap dots, are studied. Time-resolved and spectral selective techniques are used to distinguish between the direct and indirect QDs. The exciton fine structure is studied by means of optical alignment and optical orientation techniques in magnetic fields applied in the Faraday or Voigt geometries. A drastic difference in emission polarization is found for the excitons in the direct QDs involving a $\Gamma$-valley electron and the excitons in the indirect QDs contributed by an $X$-valley electron. We show that in the direct QDs the exciton spin dynamics is controlled by the anisotropic exchange splitting, while in the indirect QDs it is determined by the hyperfine interaction with nuclear field fluctuations. The anisotropic exchange splitting is determined for the direct QD excitons and compared with model calculations.

Magnetically Tuned Kondo Effect in a Molecular Double Quantum Dot: Role of the Anisotropic Exchange

We investigate theoretically and experimentally the singlet-triplet Kondo effect induced by a magnetic field in a molecular junction. Temperature dependent conductance, $G(T)$, is calculated by the numerical renormalization group, showing a strong imprint of the relevant low energy scales, such as the Kondo temperature, exchange and singlet-triplet splitting. We demonstrate the stability of the singlet-triplet Kondo effect against weak spin anisotropy, modeled by an anisotropic exchange. Moderate spin anisotropy manifests itself by lowering the Kondo plateaus, causing the $G(T)$ to deviate from a standard temperature dependence, expected for a spin-half Kondo effect. We propose this scenario as an explanation for anomalous $G(T)$, measured in an organic diradical molecule coupled to gold contacts. We uncover certain new aspects of the singlet-triplet Kondo effect, such as coexistence of spin-polarization on the molecule with Kondo screening and non-perturbative parametric dependence of an effective magnetic field induced by the leads.

Theoretical Investigation of the Electronic Structure and Magnetic Properties in Ferromagnetic Rock-Salt and Zinc Blende Structures of 3d (V)-Doped MgS

In this work, we studied the properties of vanadium doped binary MgS compound Mg1−xVxS (x = 0.125, 0.25, 0.50 and 0.75) in both ferromagnetic rock-salt and zinc-blende structures. The studied properties are structural, electronic and magnetic. The objective of this study is to explore the new dilute magnetic semiconductor systems. We have used two approximations to simulate these properties: Wu–Cohen generalized gradient approximation for structural properties, and the modified Becke–Johnson potential combined with the local density approximation for electronic and magnetic properties. The general context in which the calculations are done is based on the formalism of the spin-polarized density functional theory and the full-potential linear-augmented plane wave method. Among the various compounds studied, we have identified a ferromagnetic semiconducting behavior in the rock-salt structure. In the zinc-blende structure, we have one metallic candidate consisting of 75% V-doping of the Mg-sublattice, and all other compounds have a half-metallic ferromagnetic behavior. We conclude that the Mg1−xVxS compounds, for x = 0.125, 0.25 and 0.50, in the zinc-blende structure are a diluted magnetic semi-conductors materials. To see the effects of the exchange splitting process, the exchange constants N0α and N0β are calculated. For each concentration x, we have found the values of the total magnetic moment equal to 3 μβ excepted for the case of Mg0.25 V0.75S compound in the zinc-blende structure. The value of the total magnetic moment is due principally to V magnetic atom and to other both nonmagnetic atoms Mg and S, which show small local magnetic moments localized on their sites. The presence of ferromagnetic order in this type of compound can be explained by the p-d hybridization phenomena.

A Systematic Study of Structural, Magneto-Electronic and Thermodynamic Properties of Mg1−xCrxSe DMS Alloys in the Rock–Salt Phase for Spintronic Applications

In this work, we use the full potential linearized augmented plane wave (FP-LAPW + lo) method under the framework of spin polarization density functional theory (SP-DFT) to study the structural properties of diluted magnetic semiconductors alloys, Mg1−xCrxSe (x = 0.25, 0.50 and 0.75), in the rock–salt ferromagnetic phase by using the WC-Cohen GGA approximation. To compute the electronic and magnetic properties of our compounds, we have used the Tran Blaha modified Becke–Johnson potential (TB-mBJ) combined with PBE approximation. The results of electronic properties show that our compounds have a half-metallic behavior with a spin polarization of 100% at the Fermi level. Moreover, at all concentrations, the magnetic moment has been estimated as equal to 4.0 (μB). Furthermore, to validate the effects resulting from the exchange splitting process, we calculate the values of the spin-exchange constants N0α and N0β, respectively. Finally, we present in detail the effects of the temperature and the pressure on some macroscopic thermodynamic parameters by using the quasi-harmonic Debye model.

Surface multiferroics in silicon enabled by hole-carrier doping

We predict a coexistence of magnetic and electric orders on clean Si(0 0 1) surfaces by first-principles calculations. Upon hole-carrier doping, the Si surfaces can be ferromagnetic, with polarized spins concentrated in an atom-thick space near the surface, due to an exchange splitting of localized s-like surface states on surface Si dimers. The surface magnetization can be controlled by reorienting the electric polarization of Si dimers, manifested as a transition from the magnetic antiferroelectric ground state to ferroelectric p(2 × 1) reconstruction that can be driven by an in-plane external electric field. The coupling between magnetic and electric orders can be further enhanced by strain silicon technology, rendering the Si surfaces as the first metal-free material displaying a multiferroic behavior.

Phase detection of spin waves in yttrium iron garnet and metal induced nonreciprocity

We report experiments which characterize spin wave propagation in a thin (111) yttrium iron garnet film for arbitrary angles between the in-plane magnetic field and the mode wavevectors. By measuring the magnetic field evolution of the phase of the wave traveling across the film, we deduce the frequency dependence of the wavevector, the dispersion relation, from which the mode velocity follows. Additionally, we observe multiple nodes in the regime of the propagating Damon-Eshbach mode; these arise from avoided crossings associated with the higher, exchange split, standing wave modes along the film normal, the positions of which correlate with the direct absorption measurements of their positions. This information allows a determination of the exchange parameter. Using this technique, we examine the nonreciprocity in spin wave propagation that results from an adjacent metal layer.

Magnetic anisotropy of ferromagnetic metals in low-symmetry systems

We have constructed an analytic formula to treat the perpendicular magnetic anisotropy energy in ferromagnetic metals with low symmetry, such as C4V and C3V. We find that the anisotropy energy is proportional to a part of the expectation values of the orbital angular momentum and magnetic dipole operator. Although the result is similar to the model proposed by Laan (1998) [2], we have derived a concrete expression for the spin-flip virtual excitation process term, which can be dominant in atoms with small magnetic moments and/or small exchange splitting. Pt monatomic layer with proximity-induced spin polarization grown on Fe is an example of this. Other multilayer systems such as Co/Pd and Co/Ni, and bilayer systems such as Fe(CoB)/MgO can be discussed similarly. Moreover, the relation between perpendicular magnetic anisotropy energy and measurable physical parameters is discussed based on X-ray magnetic circular dichroism spectroscopy.

Ferromagnetism in Mn and Fe doped ZrO2 by ab-initio calculations

The aim of this work is to probe the magnetic properties of the compound ZrO2 doped by Mn and Fe, respectively. We have studied such properties of this system using the combination of the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA). The stability between the ferromagnetic and the spin-glass states is discussed by comparing their total energies. We have shown that the Zr substituted with Mn/Fe induces ferromagnetism in the compound. Therefore, the half-metallic characteristics have been investigated. Additionally, we have calculated the polarization using the density of carriers for each concentration. Besides, we have applied the mean-field approximation to estimate the high Curie temperature (TC) for concentrations approximately around the percolation threshold. The computed Curie temperatures are found to be higher than the room temperature in the both cases of Mn/Fe. These properties make these compounds as potential candidates for spintronics materials. Finally, we have studied the fluctuations of the crystal field and the exchange splittings as a function of the impurity concentrations.

Role of dilution on the electronic structure and magnetic ordering of spinel cobaltites

By means of the first-principles density functional theory ($\mathrm{DFT}+U$) calculations and experiments, we investigate the role of dilution on the structural, magnetic, electronic, and optical properties of the antiferromagnetic (AFM) spinel ${\mathrm{Co}}_{3}{\mathrm{O}}_{4}$ having N\'eel temperature $({T}_{\text{N}})\ensuremath{\sim}30$ K. As the octahedral cobalt site of spinel lattice is diluted with Ge, Al, Ti, Ru, and Sn cations, we observe a substantial increase in the size of the unit cell as well as destruction of the long-range magnetic ordering with a spin-orbit compensation effect. The ferrimagnetic ordering in diluted inverse spinels such as ${\mathrm{Co}}_{2}\mathrm{\ensuremath{\Sigma}}{\mathrm{O}}_{4}$ ($\mathrm{\ensuremath{\Sigma}}$ = Ti and Sn) emerges due to the difference in the magnetic moments of two sublattices A (3.87 ${\ensuremath{\mu}}_{\text{B}}$) and B (4.16 ${\ensuremath{\mu}}_{\text{B}}$ for ${\mathrm{Co}}_{2}{\mathrm{SnO}}_{4}$ and 5.19 ${\ensuremath{\mu}}_{\text{B}}$ for ${\mathrm{Co}}_{2}{\mathrm{TiO}}_{4}$). Experiments and DFT calculations indicate antiferromagnetic configuration for ${\mathrm{Co}}_{3}{\mathrm{O}}_{4}$, ${\mathrm{Co}}_{2}{\mathrm{AlO}}_{4}$ (${T}_{\text{N}}\ensuremath{\sim}4.8$ K) spinels with an equal and opposite moment of $\ensuremath{\sim}2.60$ ${\ensuremath{\mu}}_{\text{B}}$ in tetrahedral sites of divalent Co ions and negligible contribution from trivalent B-site Co due to the complete filling of ${t}_{2g}$ levels having a giant crystal field of $\ensuremath{\sim}2.5$ and 1.8 eV, respectively. However, in ${\mathrm{Co}}_{2}{\mathrm{GeO}}_{4}$ (${T}_{\text{N}}\ensuremath{\sim}20.4$ K) case AFM behavior originates due to the opposite spins at octahedral sites of divalent Co ions. The remaining spinels ${\mathrm{Co}}_{2}{\mathrm{TiO}}_{4}$ (${T}_{\text{N}}\ensuremath{\sim}47.8$ K), ${\mathrm{Co}}_{2}{\mathrm{RuO}}_{4}$ (${T}_{\text{N}}\ensuremath{\sim}16$ K), and ${\mathrm{Co}}_{2}{\mathrm{SnO}}_{4}$ (${T}_{\text{N}}\ensuremath{\sim}41$ K) are more favorable to ferrimagnetic structure as evident from our magnetization measurements with a different temperature dependence of magnetic moments A(T) and B(T) at tetrahedral A and octahedral B sites, respectively. The variation in the energy band gap (${E}_{g}=1.68\ensuremath{\rightarrow}3.28$ eV for ${\mathrm{Co}}_{2}{\mathrm{RuO}}_{4}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}{\mathrm{Co}}_{2}{\mathrm{GeO}}_{4}$) obtained from $\mathrm{DFT}+U$ calculations are in good agreement with our experimental results (${E}_{g}=1.52\ensuremath{\rightarrow}3.16$ eV) obtained from the diffusive reflectance spectroscopy. The extent of exchange splitting ${\mathrm{\ensuremath{\Delta}}}_{\text{EX}}^{{e}_{g}}$ of tetrahedral ${\mathrm{Co}}^{2+}$ varies between 1.8 and 1.3 eV for ${\mathrm{Co}}_{3}{\mathrm{O}}_{4}$ and ${\mathrm{Co}}_{2}{\mathrm{AlO}}_{4}$, respectively. However, ${\mathrm{\ensuremath{\Delta}}}_{\text{EX}}^{{t}_{2g}}$ exhibits a decreasing trend ($5.2\ensuremath{\rightarrow}3.6$ eV for ${\mathrm{Co}}_{3}{\mathrm{O}}_{4}\ensuremath{\rightarrow}{\mathrm{Co}}_{2}{\mathrm{SnO}}_{4}$) with increasing the lattice parameter, except for cobalt-orthogermanate ${\mathrm{Co}}_{2}{\mathrm{GeO}}_{4}$.

Spin-orbital coupling and magnetic properties of Ir-based double perovskites with different 5dn (n = 3, 4, 5) states

We have investigated the spin and orbital moments of Ir-based double perovskites with 5dn (n = 3, 4, 5) states by local spin-density approximation with spin-orbital coupling and Hubbard correlation (LSDA+SOC+U). Our calculations reveal that the ratio of orbital to spin momentum Lz/Sz approaches to certain values for the double perovskites with different 5dn (n = 3, 4, 5) shell fillings. Based on d orbits, a spin-orbital coupling model with exchange splitting is proposed and it can well describe the ratio of angular momentums for the compounds. Our model calculations reveal that Lz/Sz is determined by the exchange splitting, spin-orbital coupling as well as the state of shell filling. Our model is well corroborated by the experiments and density-functional calculations.

All-d-metal equiatomic quaternary Heusler hypothetical alloys ZnCdTMn (T = Fe, Ru, Os, Rh, Ir, Ni, Pd, Pt): A first-principle investigation of electronic structures, magnetism, and possible martensitic transformations

Abstract A new series of Zinc-based all-d-metal equiatomic quaternary Heusler hypothetical alloys ZnCdTMn (T = Fe, Ru, Os, Rh, Ir, Ni, Pd, Pt) were designed, and their ground state, electronic structures, magnetism, and possible martensitic transformations, as well as the competition between the austenitic phase and the martensitic phase, were studied in this work. ZnCdTMn alloys have large magnetic moments, all larger than 3 µB, which mainly come from the Mn atom due to its strong exchange splitting. It is worth noting that the magnetic moment of ZnCdFeMn is quite considerable (Mt = 6.0202 μB), mainly due to the Mn and Fe atoms, both of which have large magnetic moments. Additionally, first-principles calculation indicated that the martensitic phase has a lower energy than the cubic phase; therefore, a possible martensitic transformation from cubic to tetragonal is likely to occur in ZnCdTMn. More importantly, the phase transformations can be tuned by the uniform strain. The energy difference ΔEM is defined as the difference in total energy between the martensitic and cubic states; a quite large value of ΔEM about 0.5 eV was discovered in ZnCdOsMn, compared with in other Heusler alloys. The ΔEM can also be regulated by the uniform strain. For different substances, the relationship between ΔEM and V opt + X % V opt for ZnCdTMn (T = Fe, Ru, Os, Rh) is different. We hope this work can provide guidance for researchers to further explore and study new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

Unique Gap Structure and Symmetry of the Charge Density Wave in Single-Layer VSe_{2}.

Single layers of transition metal dichalcogenides (TMDCs) are excellent candidates for electronic applications beyond the graphene platform; many of them exhibit novel properties including charge density waves (CDWs) and magnetic ordering. CDWs in these single layers are generally a planar projection of the corresponding bulk CDWs because of the quasi-two-dimensional nature of TMDCs; a different CDW symmetry is unexpected. We report herein the successful creation of pristine single-layer VSe_{2}, which shows a (sqrt[7]×sqrt[3]) CDW in contrast to the (4×4) CDW for the layers in bulk VSe_{2}. Angle-resolved photoemission spectroscopy from the single layer shows a sizable (sqrt[7]×sqrt[3]) CDW gap of ∼100 meV at the zone boundary, a 220K CDW transition temperature twice the bulk value, and no ferromagnetic exchange splitting as predicted by theory. This robust CDW with an exotic broken symmetry as the ground state is explained via a first-principles analysis. The results illustrate a unique CDW phenomenon in the two-dimensional limit.

The effect of pressure on the structural, elastic, electronic, magnetic, and optical properties of Mo-doped ZnSe alloy

Abstract We studied the effect of pressure on the structural, elastic, electronic, magnetic, and optical properties of Mo-doped ZnSe alloy based on spin-polarized first-principles calculations using the generalized gradient approximation (GGA) + U and Heyd-Scuseria-Ernzerhof hybrid functional (HSE06) methods. The band gaps for pristine ZnSe compound were 1.152, 1.495, and 2.268 eV using the GGA, GGA + U and HSE06 methods, respectively. The Zn1−xMoxSe (x = 0.03125, 0.0625, and 0.125) alloys were half-metallic (HM) using the GGA + U method which could be used in spintronic devices. The Zn1−xMoxSe (x = 0.50, 0.75, and 1.00) alloys were metallic, and the Zn0.75Mo0.25Se alloy was HM using the GGA + U method. The Zn1−xMoxSe (x = 0.25 and 0.50) alloys were HM, and the Zn1−xMoxSe (x = 0.75 and 1.00) alloys were metallic using the HSE06 method. The spin-down band gap E g and HM band gap E g HM increased with increasing pressure using both the GGA + U and HSE06 methods. For both the GGA + U and HSE06 methods, the peaks of half-occupied t 2g and occupied e g states of Mo atoms shifted to the lower energy region with increasing pressure. The four 4d electrons of Mo2+ ion preponderantly induced the total magnetic moment of 4 μ B /cell. The spin exchange splitting energy Δ x ( d ) decreased, but the absolute value of exchange splitting energy Δ x ( p d ) increased with increasing pressure. The blue shift characteristic of peaks of dielectric constants e 1 ( ω ) and e 2 ( ω ) , refractive index n ( ω ) , extinction coefficient k ( ω ) , and absorption coefficient α ( ω ) with increasing pressure was observed using both the GGA + U and HSE06 methods.

Anatomy of magnetic anisotropy induced by Rashba spin-orbit interactions

Magnetic anisotropy controls the orientational stability and switching properties of magnetic states, and therefore plays a central role in spintronics. First-principles density-functional-theory calculations are able, in most cases, to provide a satisfactory description of bulk and interface contributions to the magnetic anisotropy of particular film/substrate combinations. In this paper we focus on achieving a simplified understanding of some trends in interfacial magnetic anisotropy based on a simple tight-binding model for quasiparticle states in a heavy-metal/ferromagnetic-metal bilayer film. We explain how to calculate the magnetic anisotropy energy of this model from the quasiparticle spin-susceptibility, compare with more conventional approaches using either a perturbative treatment of spin-orbit interactions or a direct calculation of the dependence of the energy on the orientation of the magnetization, and show that the magnetic anisotropy can be interpreted as a competition between a Fermi-sea term favoring perpendicular anisotropy and a Fermi-surface term favoring in-plane anisotropy. Based on this finding, we conclude that perpendicular magnetic anisotropy should be expected in an itinerant electron thin film when the spin magnetization density is larger than the product of the band exchange splitting and the Fermi level density-of-states of the magnetic state.

Electronic and Magnetic Properties of Fe Atomic Chain and Fe Atomic Plane: Anab initioStudy

The electronic and magnetic properties of Fe atomic wire and atomic plane have been theoretically investigated from full potential linearized augmented plane wave (FPLAPW) method within a frame work of density functional theory (DFT). This work is based on the comparative study of number of Fe nanochains with infinite length and infinitely spread Fe nanosheet. A most commonly adopted GGA approximation is used for electron exchange correlation. In our calculation, the property of Fe-chain is predicted to be magnetic metal with the presence of deep valley (in Spin-up DOS) and a peak (in Spin-down DOS) at Fermi level ([Formula: see text]) shows the antisymmetric DOS. The presence of antisymmetric DOS is a signature of exchange splitting between the degenerated d-states. The splitting between t[Formula: see text] states is very prominent in Fe-chain which enhances the magnetic moment. The magnetic moment decreases with the increase in number of Fe-chains.

Prediction of possible martensitic transformations in all-d-metal Zinc-based Heusler alloys from first-principles

Abstract Several newly designed Zinc-based all-d-metal Heusler alloys, Zn2MMn (M = Ru, Rh, Pd, Os, Ir), have been predicted, and their XA- and L21-type atomic-site preferences, electronic structures, magnetic properties, as well as their possible martensitic phase transformations have been studied theoretically from first principles. For cubic-type these alloys, their L21-type phase is more stable than the XA phase, that is, the two Zn atoms prefer to locate at the A (0,0,0) and C (0.5, 0.5, 0.5) positions in the lattice. Their magnetic state is ferromagnetic (FM), with a large total magnetic moment (> 3µB/f.u), and the total magnetic moment arises mainly from the Mn atom due to its strong exchange splitting. Remarkably, Zn2MMn alloys with a tetragonal martensitic structure can lower their total energies and show more stable behaviour than cubic systems. The energy difference ΔEM is defined as the difference in total energy between the martensitic and cubic states. Δ EM can be tuned by uniform strain, namely, as the lattice constant increases, Δ EM also increases. Moreover, in the case of martensitic-type Zn2RuMn and Zn2OsMn alloys, quite large c/a ratios (1.41, 1.43, respectively) can be found, which are preferable for the transformation strain effect. It is hoped that this work can motivate researchers to look for new spintronic and magnetic-intelligent materials among all-d-metal Heusler alloys.