The ruthenium content of half-metallic Mn$_2$Ru$_x$Ga thin films, with a biaxially-strained inverse Heusler structure, controls the ferrimagnetism that determines their magnetic and electronic properties. An extensive study of Mn$_y$Ru$_x$Ga films on MgO (100) substrates with $1.8 \leq y \leq 2.6$ and $x = 0.5$, 0.7 or 0.9, including crystallographic, magnetic order, magneto-transport and spin polarisation is undertaken to map specific composition-dependent properties in this versatile ternary system. A comparison of experimental densities obtained from X-ray reflectivity with calculated densities indicates full site occupancy for all compositions, which implies chemical disorder. All moments lie on the Slater-Pauling plot with slope 1 and all except $x = 0.5$, $y = 2.2$ exhibit magnetic compensation at \tcmp~below 500~K. The coercivity near \tcmp~exceeds 10~T. Increasing the Mn or Ru content raises \tcmp, but increasing Ru also decreases the spin polarisation determined by point contact Andreev reflection. Molecular field theory is used to model the temperature dependence of the net ferrimagnetic moment and three principal exchange coefficients are deduced. Marked differences in the shape of anomalous Hall and net magnetisation hysteresis loops are explained by substantial canting of the small net moment by up to \SI{40}{\degree} relative to the $c$-axis in zero field, which is a result of slight non-collinearity of the Mn$^{4c}$ sublattice moments due to competing intra-sublattice exchange interactions arising from antisite disorder and excess Mn in the unit cell. Consequences are reduced spin polarisation and an enhanced intrinsic contribution to the anomalous Hall effect. The systematic investigation of the physical properties as a function of $x$ and $y$ will guide the selection of compositions to meet the requirements for magnonic and spintronic MRG-based devices.
Large magnetocaloric effect has been observed in Mn3O4 around its ferrimagnetic transition at TN = 42.75 K. Field-induced isothermal entropy changes (\DeltaS) were derived from both magnetic and calorimetric techniques. The maximum |\DeltaS| and adiabatic temperature change (ΔTad) at TN are 11 J kg-1 K-1 and 1.9 K, respectively, for a magnetic field change of 20 kOe. Moreover, it is found that the complex magnetic phase transitions taking place below TN produce additional -but smaller- features on \DeltaS(T).
The single crystal study of CaBaCo4O7, a non collinear ferrimagnet (TC=64K), with a polar orthorhombic space group (Pbn21) between 4 K and 293 K, shows the appearance below TC of a large electric polarization along its c axis, reaching 17mC.m-2 at 10K. At 62.5K, a magnetic field driven giant variation of polarization, P(9T)-P(0T)=8mC.m-2, is observed. Moreover, the present magnetoelectric measurements, are fully consistent with the m'm2' magnetic point group, strongly supporting that this oxide is also ferrotoroidic. This ferrimagnetic oxide, which belongs to the '114' structural family, opens…
Multiferroic materials, in which ferroelectric and magnetic ordering coexist, are of fundamental interest for the development of novel memory devices that allow for electrical writing and non-destructive magnetic readout operation. The great challenge is to create room temperature multiferroic materials with strongly coupled ferroelectric and ferromagnetic (or ferrimagnetic) orderings. BiFeO3 has been the most heavily investigated single-phase multiferroic to date due to the coexistence of its magnetic order and ferroelectric order at room temperature. However, there is no net magnetic moment …
We report the parameter-free, density functional theory calculations of interatomic exchange interactions and Curie temperatures of half-metallic ferrimagnetic full Heusler alloys Mn2VZ (Z=Al, Ge). To calculate the interatomic exchange interactions we employ the frozen-magnon approach. The Curie temperatures are calculated within the mean-field approximation to the classical Heisenberg Hamiltonian by solving a matrix equation for a multi-sublattice system. Our calculations show that, although a large magnetic moment is carried by Mn atoms, competing ferromagnetic (inter sublattice) and antifer…
We present the Co-Gd composition dependence of the spin-Hall magnetoresistance (SMR) and anisotropic magnetoresistance (AMR) for ferrimagnetic Co100-xGdx / Pt bilayers. With Gd concentration x, its magnetic moment increasingly competes with the Co moment in the net magnetization. We find a nearly compensated ferrimagnetic state at x = 24. The AMR changes sign from positive to negative with increasing x, vanishing near the magnetization compensation. On the other hand, the SMR does not vary significantly even where the AMR vanishes. These experimental results indicate that very different scatte…
Magnetocaloric effect (MCE) in TbCo2-xFex has been studied by dc magnetization measurements.On substituting Fe in TbCo2, not only the magnetic transition temperature is tuned to room temperature, but also the operating temperature range for MCE is increased from 50 K for TbCo2 to 95 K for TbCo1.9Fe0.1. The maximum magnetic entropy change (-ΔSM) for TbCo1.9Fe0.1 is found to be 3.7 J kg-1 K-1 for a 5 T field change, making it a promising candidate for magnetic refrigeration near room temperature. The temperature dependent neutron diffraction study shows a structural phase transition (from cubic …
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 external fields. Ferrimagnetism can be either found in perfect Heusler compounds or achieved through the creation of defects in ferromagnetic Heusler alloys.
We report a systematic study of current-induced perpendicular magnetization switching in W/Co$_{x}$Tb$_{1-x}$/Al thin films with strong perpendicular magnetic anisotropy. Various Co$_{x}$Tb$_{1-x}$ ferrimagnetic alloys with different magnetic compensation temperatures are presented. The systems are characterized using MOKE, SQUID and anomalous Hall resistance at different cryostat temperature ranging from 10 K to 350 K. The current-switching experiments are performed in the spin-orbit torque geometry where the current pulses are injected in plane and the magnetization reversal is detected by m…
The mixed manganite-cuprate CaCu3Mn4O12 is found, using density functional methods, to be a narrow gap (90 meV calculated) ferrimagnetic semiconductor. Cu (formally S=1/2) antialigns with Mn (formally S=3/2), and the net spin moment is 9 μ_B consistent with the formal spins. Holes have Cu d_{xy}-O p_σ (i.e. antibonding dpσ) character with spins aligned antiparallel to the net magnetization; electrons have the opposite spin and have mixed Cu d_{xy} - Mn e_g character. Thermally excited electrons and holes will each be fully spin polarized, but in opposite directions. The properties of this mate…
We predict through our first-principles calculations that four double perovskite oxides of Bi2ABO6 (AB = FeMo, MnMo, MnOs, CrOs) are half-metallic ferrimagnets. Our calculated results shows that the four optimized structures have negative formation energy, from -0.42 to -0.26 eV per formula unit, which implies that they could probably be realized. In the case of Bi2FeMoO6, the half-metallic gap and Curie temperature are predicted to reach to 0.71 eV and 650 K, respectively, which indicates that high spin polarization could be kept at high temperatures far beyond room temperature. It is believe…
Although several multiferroic materials/heterostructures have been extensively studied, finding strong magnetoelectric couplings for the electric field control of the magnetization remains challenging. Here, a novel interfacial magnetoelectric coupling based on three components (ferroelectric dipole, magnetic moment, and antiferromagnetic order) is analytically formulated. As an extension of carrier-mediated magnetoelectricity, the new coupling is shown to induce an electric-magnetic hysteresis loop. Realizations employing BiFeO$_3$ bilayers grown along the [$111$] axis are proposed. Without i…
A ternary ferrimagnetic half-metal, constructed through substituting 25% Fe for Mn in zincblende semiconductor MnTe, is predicted in terms of accurate first-principles calculations. It has a large half-metallic (HM) gap of 0.54eV and its ferrimagnetic order is very stable against other magnetic fluctuations. The HM ferrimagnetism is formed because the complete moment compensation in the antiferromagnetic MnTe is replaced by an uncomplete one in the Fe-substituted MnTe. This should make a novel approach to new HM materials. The half-metal could be fabricated because Fe has good affinity with Mn…
Cerium diantimonide (CeSb$_2$) is one of a family of rare earth based magnetic materials that exhibit metamagnetism, enabling control of the magnetic ground state through an applied magnetic field. At low temperatures, CeSb$_2$ hosts a rich phase diagram with multiple magnetically ordered phases for many of which the order parameter is only poorly understood. In this paper, we report a study of its metamagnetic properties by Scanning Tunneling Microscopy (STM) and magnetization measurements. We use STM measurements to characterize the sample magnetostriction with sub-picometer resolution from …
We have performed point contact spectroscopy measurements on a sample constituted by a metallic ferromagnetic oxide (SrRuO_3) bottom electrode and a tunnel ferrimagnetic (CoFe_2O_4) barrier. Andreev reflection is observed across the tunnel barrier. From the comparison of Andreev reflection in SrRuO3 and across the CoFe_2O_4 barrier we infer that the ferrimagnetic barrier has a spin filter efficiency not larger than +13%. The observation of a moderate and positive spin filtering is discussed in the context of the microstructure of the barriers and symmetry-related spin filtering effects.
Nowdays, multiferroic materials with magnetoelectric coupling have many real-world applications in the fields of novel memory devices. It is challenging is to create multiferroic materials with strongly coupled ferroelectric and ferrimagnetic orderings at room temperature. The single crystal of ferric selenide (Fe3Se4) shows type-II multiferroic due to the coexistence of ferroelectric as well as magnetic ordering at room temperature. We have investigated the lattice instability, electronic structure, ferroelectric, ferrimagnetic ordering and transport properties of ferroelectric metal Fe3Se4. …
Effect of Ge substitution on first order ferrimagnetic (FRI) - antiferromagnetic (AFM) transition in Mn$_2$Sb has been studied. It shows that transition temperature (T$_t$) can be tuned between 119~K - 271~K by substituting 2.5-10\% Ge at Sb site in Mn$_2$Sb. The variation of density of state at Fermi level N(E$_f$) with Ge substitution shows that dN(E)/dE is positive at E$_f$ in the AFM state. With the application of magnetic field T$_t$ shifts to low temperature, which results in a giant negative magnetoresistance (MR) reaching a value of 70\% for 2.5\% substitution. Our results show that FR…
Nanoparticles of the ferrimagnetic epsilon-Fe2O3 oxide have been synthesized by sol-gel method. Here, we report on the measurements of the dielectric permittivity as a function of temperature, frequency and magnetic field. It is found that, coinciding with the transition from collinear ferrimagnetic ordering to an incommensurate magnetic state occurring at about 100 K, there is an abrupt change (about 30 %) of permittivity suggesting the existence of a magnetoelectric coupling in this material. Indeed, magnetic field dependent measurements at 100 K have revealed an increase of the permittivity…
Recent advances in antiferromagnetic spin dynamics using rare-earth (RE) and transition-metal (TM) ferrimagnets have attracted much interest for spintronic devices with a high speed and density. In this study, the spin wave properties in the magnetostatic backward volume mode and surface mode in RE-TM ferrimagnetic $Gd_{x}Co_{1-x}$ films with various composition x are investigated using spin wave spectroscopy. The obtained group velocity and attenuation length are well explained by the ferromagnet-based spin wave theory when the composition of $Gd_{x}Co_{1-x}$ is far from the compensation poin…
Amorphous TbFeCo thin films sputter deposited at room temperature on thermally oxidized Si substrate are found to exhibit strong perpendicular magnetic anisotropy (PMA). Atom probe tomography (APT), scanning transmission electron microscopy (STEM), and energy dispersive spectroscopy (EDS) mapping have revealed two nanoscale amorphous phases with different Tb atomic percentages distributed within the amorphous film. Exchange bias accompanied by bistable magneto-resistance states has been uncovered near room temperature by magnetization and magneto-transport measurements. The exchange anisotropy…
We present experimental control of the magnetic anisotropy in a gadolinium iron garnet (GdIG) thin film from in-plane to perpendicular anisotropy by simply changing the sample temperature. The magnetic hysteresis loops obtained by SQUID magnetometry measurements unambiguously reveal a change of the magnetically easy axis from out-of-plane to in-plane depending on the sample temperature. Additionally, we confirm these findings by the use of temperature dependent broadband ferromagnetic resonance spectroscopy (FMR). In order to determine the effective magnetization, we utilize the intrinsic adva…
The manipulation of magnetism with a gate voltage is expected to lead the way towards the realization of energy-efficient spintronics devices and high-performance magnetic memories. Exploiting magneto-ionic effects under micro-patterned electrodes in solid-state devices adds the possibility to modify magnetic properties locally, in a non-volatile and reversible way. Tuning magnetic anisotropy, magnetization and Dzyaloshinskii-Moriya interaction allows modifying at will the dynamics of non trivial magnetic textures such as skyrmions and chiral domain walls in magnetic race tracks. In this work,…
Competing exchange interactions can produce complex magnetic states together with spin-induced electric polarizations. With competing interactions on alternating triangular and kagome layers, the swedenborgite CBO may have one of the largest measured spin-induced polarizations of about 1700 nC/cm$^2$ below its ferrimagnetic transition temperature at 70 K. Powder neutron-diffraction data, magnetization measurements, and spin-wave resonance frequencies in the THz range reveal that the complex spin order of multiferroic CBO can be described as a triangular array of c-axis chains ferrimagnetically…
Ferrimagnetic insulators (FiMI) have been intensively used in microwave and magneto-optical devices as well as spin caloritronics, where their magnetization direction plays a fundamental role on the device performance. The magnetization is generally switched by applying external magnetic fields. Here we investigate current-induced spin-orbit torque (SOT) switching of the magnetization in Y3Fe5O12 (YIG)/Pt bilayers with in-plane magnetic anisotropy, where the switching is detected by spin Hall magnetoresistance. Reversible switching is found at room temperature for a threshold current density o…
Half-metallic ferromagnets show 100% spin-polarization at the Fermi level and are ideal candidates for spintronic applications. Despite the extensive research in the field, very few materials have been discovered so far. Here we present results of electronic band structure calculations based on density functional theory and extensive physical-property measurements for Fe3Se4 revealing signatures of half-metallicity. The spin-polarized electronic band structure calculations predict half-metallic ferrimagnetism for Fe3Se4. The electrical resistivity follows exponentially suppressed electron-magn…
In attempt to explore half-metallic properties of the double perovskites Sr2-xYxVMoO6 and Sr2-xYxVTcO6, we construct an effective low-energy model, which describes the behavior of the t2g-states of these compounds. All parameters of such model are derived rigorously on the basis of first-principles electronic structure calculations. In order to solve this model we employ the optimized effective potential method and treat the correlation interactions in the random phase approximation. Although correlation interactions considerably reduce the intraatomic exchange splitting in comparison with the…
The effect of the Fe-Ga ratio on the magnetic and electric properties of the multiferroic Ga2-xFexO3 compound has been studied in order to determine the composition range exhibiting magnetic and electric orders coexistence and their critical temperatures. A magnetoelectric phase diagram, showing the evolution of both the Neel magnetic ordering temperature and the electric ordering temperature, versus the iron content has been established for x values between 0.9 and 1.4. While the ferrimagnetic Neel temperature increases with the iron content, the electric ordering temperature shows an opposit…
We experimentally demonstrate that in magnetostrictive ferrimagnetic single crystal of CoFe2O4 there is clear correlation between magnetostriction and magnetoreflection of unpolarized light in the infrared range. The influence of magnetic field on specular reflection is likely to be indirect: application of a magnetic field results in strong strain and deformation of the crystal lattice, which leads to the change in electron energy structure and hence reflection spectrum.
Inspired by chains of ferrimagnetic nanocrystals (NCs) in magnetotactic bacteria (MTB), the synthesis and detailed characterization of ferrimagnetic magnetite NC chain-like assemblies is reported. An easy green synthesis route in a thermoreversible gelatin hydrogel matrix is used. The structure of these magnetite chains prepared with and without gelatin is characterized by means of transmission electron microscopy, including electron tomography (ET). These structures indeed bear resemblance to the magnetite assemblies found in MTB, known for their mechanical flexibility and outstanding magneti…
Synthesizing half-metallic fully-compensated ferrimagnets that form in the inverse Heusler phase could lead to superior spintronic devices. These materials would have high spin polarization at room temperature with very little fringing magnetic fields. Previous theoretical studies indicated that Cr2CoAl should form in a stable inverse Heusler lattice due to its low activation energy. Here, stoichiometric Cr2CoAl samples were arc-melted and annealed at varying temperatures, followed by studies of their structural and magnetic properties. High-resolution synchrotron X-ray diffraction revealed a …
Recently, theorists have predicted many materials with a low magnetic moment and large spin-polarization for spintronic applications. These compounds are predicted to form in the inverse Heusler structure, however, many of these compounds have been found to phase segregate. In this study, ordered Cr2CoGa thin films were synthesized without phase segregation using molecular beam epitaxy. The present as-grown films exhibit a low magnetic moment from antiferromagnetically coupled Cr and Co atoms as measured with SQUID magnetometry and soft X-ray magnetic circular dichroism. Electrical measurement…
Epitaxial thin films of the half-metallic Xa-compound Mn2CoGa (Hg2CuTi prototype) were prepared by dc magnetron co-sputtering with different heat treatments on MgO (001) substrates. High-quality films with a bulk magnetization of 1.95(5)μ_B per unit cell were obtained. The L3,2 x-ray magnetic circular dichroism spectra agree with calculations based on density functional theory (DFT) and reveal the antiparallel alignment of the two inequivalent Mn moments. X-ray magnetic linear dichroism, in good agreement with theory as well, allows to distinguish between itinerant and local Mn moments. Based …
The cubic Heusler alloy Ru$_{2-x}$Mn$_{1+x}$Al is grown in thin film form on MgO and MgAl$_2$O$_4$ substrates. It is a highly spin-polarised ferrimagnetic metal, with weak magnetocrystalline anisotropy. Although structurally and chemically similar to $\text{Mn}_2\text{Ru}_x\text{Ga}$, it does not exhibit ferrimagnetic compensation, or large magneto galvanic effects. The differences are attributed to a combination of atomic order and the hybridisation with the group 13 element Al or Ga. The spin polarisation is around 50 to 60 %. There is a gap in the density of states just above the Fermi leve…
Single-phase polycrystalline La2MnVO6 samples were synthesized by arc melting and characterized by X-ray diffraction, magnetization and resistivity measurements. We find that the compound has cubic (space group), partly ordered double perovskite structure. The sample exhibits ferrimagnetic behavior and variable-range hopping conductivity. We conclude based on the magnetic properties that both Mn and V ions are trivalent; moreover, the Mn3+ ions are in a high-spin state, which is the reason that the compound is not a half-metallic antiferromagnet.
Combining density-functional theory calculations with many-body Green's-function technique, we reveal that the macroscopic magnetization in half-metallic antiferromagnets does not vanish at finite temperature as for the T=0 limit. This anomalous behavior stems from the inequivalent magnetic sublattices which lead to different intrasublattice exchange interactions. As a consequence, the spin fluctuations suppress the magnetic order of the sublattices in a different way leading to a ferrimagnetic state at finite temperatures. Computational results are presented for the half-metallic antiferromag…
THz magnetization dynamics is excited in ferrimagnetic thulium iron garnet with a picosecond, single-cycle magnetic field pulse and seen as a high-frequency modulation of the magneto-optical Faraday effect. Data analysis combined with numerical modelling and evaluation of the effective Lagrangian allow us to conclude that the dynamics corresponds to the exchange mode excited by Zeeman interaction of the THz field with the antiferromagnetically coupled spins. We argue that THz-pump IR-probe experiments on ferrimagnets offer a unique tool for quantitative studies of dynamics and mechanisms to co…
Static and dynamic magnetic properties of a ferrimagnetic [Fe(35A)/Gd(50A)]x12 superlattice were investigated in a wide 4-300 K temperature range using magneto-optical Kerr effect (MOKE) and ferromagnetic resonance (FMR) techniques. The multilayer structure was sputtered on a transparent glass substrate which made it possible to perform MOKE measurements on both Fe and Gd terminated sides of the superlattice. These experiments allowed us to detect a transition between field-aligned and canted magnetic states on both sides of the film and to distinguish between the bulk and surface twisted phas…
Compensation-Like Temperature and Spin-Flip Switch in Strained Thulium Iron Garnet Thin Films: Tuning Sublattice Interactions for Ferrimagnetic Spintronics
We show that misfit strain originated from the film-substrate lattice mismatch strongly increases the value of the quadratic magnetoelectric coupling. The giant magnetoelectric coupling, size effects and misfit strain cause strong changes of ferroic films phase diagrams at zero external magnetic and electric fields, in particular, the transformation of antiferromagnetic phase into ferromagnetic or ferrimagnetic ones for compressive or tensile misfit strains correspondingly as well as thickness induced paramagnetic or/and paraelectric phases appearance. Ferromagnetism appearance and magnetoelec…
We report on first-principles spin-polarised quantum transport calculations (from NEGF+DFT) in MgO-spaced magnetic tunnel junctions (MTJs) based on two different Mn-based Heusler ferrimagnetic metals, namely Mn$_3$Al and Mn$_3$Ga in their tetragonal DO$_{22}$ phase. The former is a fully compensated half-metallic ferrimagnet, while the latter is a low-moment high-spin-polarisation ferrimagnet, both with a small lattice mismatch from MgO. In identical symmetric and asymmetric interface reconstructions across a 3-monolayer thick MgO barrier for both ferrimagets, the linear response (low-voltage)…
The interfacial Dzyaloshinskii-Moriya interaction (DMI) in multilayers of heavy metal and ferromagnetic metals enables the stabilization of novel chiral spin structures such as skyrmions. Magnetic insulators, on the other hand can exhibit enhanced dynamics and properties such as lower magnetic damping and therefore it is of interest to combine the properties enabled by interfacial DMI with insulating systems. Here, we demonstrate the presence of interfacial DMI in heterostructures that include insulating magnetic layers. We use a bilayer of perpendicularly magnetized insulating thulium iron ga…
We employ density functional theory using the modified Becke-Johnson (mBJ) approach to investigate the electronic and magneto-optical properties of N-doped NaTaO$_3$. The mBJ results reveal a half metallic nature of NaTaO$_2$N, in contrast to results obtained by the generalized gradient approximation. We find a giant polar Kerr rotation of 2.16$^{\circ}$ at 725 nm wave length (visible region), which is high as compared to other half metallic perovskites as well as to the prototypical half metal PtMnSb.
We measured the spin-orbit torques (SOTs), current-induced switching, and domain wall (DW) motion in synthetic ferrimagnets consisting of Co/Tb layers with differing stacking order grown on a Pt underlayer. We find that the SOTs, magnetic anisotropy, compensation temperature and SOT-induced switching are highly sensitive to the stacking order of Co and Tb and to the element in contact with Pt. Our study further shows that Tb is an efficient SOT generator when in contact with Co, such that its position in the stack can be adjusted to generate torques additive to those generated by Pt. With opti…
We present a comparative study of both the magnetic and magnetotransport properties for two members of the perovskite solid solution LaNixCo1-xO3 (x=0.2, 0.6) located on opposite sides of the chemically induced metal-to-insulator transition. LaNi0.6Co0.4O3 exhibits metallic behavior and small but negative magnetoresistance, whereas LaNi0.2Co0.8O3 exhibits semiconducting behavior and giant negative magnetoresistance at low temperatures. On the other hand, we observe pronounced similarities in the magnetic properties of both compounds. A consistent explanation regarding the origin of the magneto…
Heusler alloys are widely studied due to their interesting structural and magnetic properties, like magnetic memory shape ability, coupled magneto-structural phase transitions and half-metallicity; ruled, for many cases, by the valence electrons number ($N_v$). The present work focuses on the magnetocaloric potentials of half-metals, exploring the effect of $N_v$ on the magnetic entropy change, preserving half-metallicity. The test bench is the Si-rich side of the half-metallic series Fe$_2$MnSi$_{1-x}$Ga$_x$. From the obtained experimental results it was possible to obtain $|ΔS|_{max}=ΔH^{0.8…
Motivated by the observation of nonmetallic nature in double perovskite Ca2CrReO6 and Ca2FeReO6 with high magnetic Curie temperatures of 360 and 522 K, we systematically investigate the structural, electronic, and magnetic properties of Ca2MReO6 (M=Cr,Fe) using the full-potential linear augmented plane wave (FP-LAPW) method within the density functional theory. Our full optimization confirms the stable ground-state structure with $P2_1/n$ symmetry. The modified Becke-Johnson (mBJ) exchange potential is used for investigating electronic structures. Our mBJ calculation shows that they are both f…
Orientation-resolved ultrafast spin reorientation dynamics in ferrimagnetic DyCo$_5$
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie(马克斯·玻恩非线性光学和超快光谱学研究所);Leibniz-Institut für Kristallzüchtung(莱布尼茨晶体生长研究所);European XFEL(欧洲X射线自由电子激光设施);Technische Universität Berlin, Institut für Optik und Atomare Physik(柏林工业大学光学与原子物理研究所)