Based on the analytical solution of electromagnetic scattering by a uniaxial anisotropic sphere in the spectral domain, an analytical solution to the electromagnetic scattering by a uniaxial left-handed materials (LHM...Based on the analytical solution of electromagnetic scattering by a uniaxial anisotropic sphere in the spectral domain, an analytical solution to the electromagnetic scattering by a uniaxial left-handed materials (LHMs) sphere is obtained in terms of spherical vector wave functions in a uniaxial anisotropic LHM medium. The expression of the analytical solution contains only some one-dimensional integral which can be calculated easily. Numerical results show that Mie series of plane wave scattering by an isotropic LHM sphere is a special case of the present method. Some numerical results of electromagnetic scattering of a uniaxial anisotropic sphere by a plane wave are given.展开更多
We investigate the propagation of electromagnetic waves in stratified anisotropic dielectric-magnetic materialsusing the integral equation method (IEM).Based on the superposition principle, we use Hertz vector formula...We investigate the propagation of electromagnetic waves in stratified anisotropic dielectric-magnetic materialsusing the integral equation method (IEM).Based on the superposition principle, we use Hertz vector formulations ofradiated fields to study the interaction of wave with matter.We derive in a new way the dispersion relation, Snell's lawand reflection/transmission coefficients by self-consistent analyses.Moreover, we find two new forms of the generalizedextinction theorem.Applying the IEM, we investigate the wave propagation through a slab and disclose the underlyingphysics, which are further verified by numerical simulations.The results lead to a unified framework of the IEM for thepropagation of wave incident either from a medium or vacuum in stratified dielectric-magnetic materials.展开更多
Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as ...Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as magnetoelectric(ME)coupling effect at room temperature(RT)in this system have not been demonstrated yet.In this study,epitaxial SmFeO3 films were successfully prepared onto tensile-strain Nb-SrTiO3(Nb-STO)substrates by a pulsed laser deposition(PLD)method.Measurement results show that the films exhibit obvious ferromagnetic and ferroelectric orders at RT.Meanwhile,the magnetic anisotropy gradually changes from out-of-plane(OP)to in-plane(IP)direction with increasing film thickness,which is attributed to the variations of O 2p-Fe 3d hybridization intensity and Fe 3d-orbit occupancy caused by the strain-relaxed effect.Moreover,electrically driven reversible magnetic switching further proves that the SmFeO3 films exhibit the RT ME coupling effect,suggesting promising applications in new-generation electric-write magnetic-read data storage devices.展开更多
We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for ...We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.展开更多
The application of antimony sulfide(Sb_(2)S_(3))has been limited mainly to the energy storage and photoelectric conversion fields.However,in this work,the application of Sb_(2)S_(3) is extended to the field of electro...The application of antimony sulfide(Sb_(2)S_(3))has been limited mainly to the energy storage and photoelectric conversion fields.However,in this work,the application of Sb_(2)S_(3) is extended to the field of electromagnetic(EM)wave absorption for the first time.High-permittivity Sb_(2)S_(3) singlecrystal nanorods were prepared successfully and exhibited excellent performance,with a low reflection loss of -65.9 dB(13.0 GHz,3.8 mm)and an ultra-wide effective absorption bandwidth of 9.5 GHz(8.5-18.0 GHz,4.1 mm).After excluding the general absorption mechanisms,including conductive losses,interfacial polarization,and dipole polarization,the distinctive single-crystal volume polarization affected by shape anisotropy was proposed.This work not only meets the challenge of a single-component dielectric material design but also introduces a new concept for construction of efficient dielectric EM wave absorption material.展开更多
Detailed studies of the structures, magnetic properties and photodimerization of a series of formato-bridged MOFs with the general formula M2(HCOO)3(4,4'-bpe)3(H20)3(X) (4,4'-bpe = 4,4'-bipyridylethylene, ...Detailed studies of the structures, magnetic properties and photodimerization of a series of formato-bridged MOFs with the general formula M2(HCOO)3(4,4'-bpe)3(H20)3(X) (4,4'-bpe = 4,4'-bipyridylethylene, M = Mn (l-X-), X- = CIO4, NO3, BF4, I-, Br-; M = Co (2-X-), X- = C104, NO3; M = Zn (3-X-), X- = NO3) were reported. Careful magnetic measurements on an ori- ented single crystal of 1-C104 determined the spin-flop magnetic phase diagram and some intrinsic parameters, such as the in- tralayer coupling d, the anisotropy field HA and the exchange field HE. Different anions can remarkably tune the magnetic properties of l-X-, especially the critical fields of the spin-flop transition. Compound 2-C104 remained paramagnetic down to 2K.展开更多
Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated....Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated. The reflect loss was less than -20 dB for all of the composites in different frequency ranges. The cube-like and walnut-like Fe3O4 composites exhibit improved complex permittivity and permeability and dual-frequency and wide bandwidth absorption characteristics, which is mainly attributed to the larger shape anisotropy. Such a high absorption property indicates that these porous Fe3O4 particles with various morphologies are very promising for electromagnetic wave absorptive materials.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 2004CB719802) and the Natural Science Foundation of Zhejiang Province (No. Y104539), China
文摘Based on the analytical solution of electromagnetic scattering by a uniaxial anisotropic sphere in the spectral domain, an analytical solution to the electromagnetic scattering by a uniaxial left-handed materials (LHMs) sphere is obtained in terms of spherical vector wave functions in a uniaxial anisotropic LHM medium. The expression of the analytical solution contains only some one-dimensional integral which can be calculated easily. Numerical results show that Mie series of plane wave scattering by an isotropic LHM sphere is a special case of the present method. Some numerical results of electromagnetic scattering of a uniaxial anisotropic sphere by a plane wave are given.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10847121,10804029,and 10904036
文摘We investigate the propagation of electromagnetic waves in stratified anisotropic dielectric-magnetic materialsusing the integral equation method (IEM).Based on the superposition principle, we use Hertz vector formulations ofradiated fields to study the interaction of wave with matter.We derive in a new way the dispersion relation, Snell's lawand reflection/transmission coefficients by self-consistent analyses.Moreover, we find two new forms of the generalizedextinction theorem.Applying the IEM, we investigate the wave propagation through a slab and disclose the underlyingphysics, which are further verified by numerical simulations.The results lead to a unified framework of the IEM for thepropagation of wave incident either from a medium or vacuum in stratified dielectric-magnetic materials.
基金This work was supported by the National Natural Science Foundation of China(51871137,51901118,51571136 and 61904099).The authors acknowledge Shanghai Synchrotron Radiation Facility at the Beamline BL08U1A and the National Synchrotron Radiation Laboratory at the Beamline BL12-a for the XAS measurements.
文摘Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material,holding great potential in novel low-power electronic devices.Nevertheless,simultaneous magnetic and ferroelectric orders as well as magnetoelectric(ME)coupling effect at room temperature(RT)in this system have not been demonstrated yet.In this study,epitaxial SmFeO3 films were successfully prepared onto tensile-strain Nb-SrTiO3(Nb-STO)substrates by a pulsed laser deposition(PLD)method.Measurement results show that the films exhibit obvious ferromagnetic and ferroelectric orders at RT.Meanwhile,the magnetic anisotropy gradually changes from out-of-plane(OP)to in-plane(IP)direction with increasing film thickness,which is attributed to the variations of O 2p-Fe 3d hybridization intensity and Fe 3d-orbit occupancy caused by the strain-relaxed effect.Moreover,electrically driven reversible magnetic switching further proves that the SmFeO3 films exhibit the RT ME coupling effect,suggesting promising applications in new-generation electric-write magnetic-read data storage devices.
基金supported by the National Natural Science Foundation of China (Grant No. 11034004)National Science Fund for Distinguished Young Scholars (Grant No. 50925103)+1 种基金Key Grant Project of Chinese Ministry of Education (Grant No. 309027)the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2010-219)
文摘We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.
基金supported by the National Natural Science Foundation of China(51572157,21902085,and 51702188)the Natural Science Foundation of Shandong Province(ZR2019QF012)+1 种基金the Fundamental Research Funds for the Central Universities(2018JC046)Young Scholars Program of Shandong University(2018WLJH25)。
文摘The application of antimony sulfide(Sb_(2)S_(3))has been limited mainly to the energy storage and photoelectric conversion fields.However,in this work,the application of Sb_(2)S_(3) is extended to the field of electromagnetic(EM)wave absorption for the first time.High-permittivity Sb_(2)S_(3) singlecrystal nanorods were prepared successfully and exhibited excellent performance,with a low reflection loss of -65.9 dB(13.0 GHz,3.8 mm)and an ultra-wide effective absorption bandwidth of 9.5 GHz(8.5-18.0 GHz,4.1 mm).After excluding the general absorption mechanisms,including conductive losses,interfacial polarization,and dipole polarization,the distinctive single-crystal volume polarization affected by shape anisotropy was proposed.This work not only meets the challenge of a single-component dielectric material design but also introduces a new concept for construction of efficient dielectric EM wave absorption material.
基金support from the National Natural Science Foundation of China (21101093, 90922033)the Natural Science Foundation of Jiangsu Province (BK2011548)
文摘Detailed studies of the structures, magnetic properties and photodimerization of a series of formato-bridged MOFs with the general formula M2(HCOO)3(4,4'-bpe)3(H20)3(X) (4,4'-bpe = 4,4'-bipyridylethylene, M = Mn (l-X-), X- = CIO4, NO3, BF4, I-, Br-; M = Co (2-X-), X- = C104, NO3; M = Zn (3-X-), X- = NO3) were reported. Careful magnetic measurements on an ori- ented single crystal of 1-C104 determined the spin-flop magnetic phase diagram and some intrinsic parameters, such as the in- tralayer coupling d, the anisotropy field HA and the exchange field HE. Different anions can remarkably tune the magnetic properties of l-X-, especially the critical fields of the spin-flop transition. Compound 2-C104 remained paramagnetic down to 2K.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51072038, 50772025 and 21001035)NECT, Outstanding Youth Foundation of Heilongjiang Province (Grant No. JC201008)+4 种基金the Natural Science Foundation of Heilongjiang Province, China (Grant No. F200828)the Ministry of Science and Technology of China (Grant No. 2008DFR20420)the Fundamental Research Funds for the Central Universities (Grant Nos. HEUCFT1010, HEUCF101016, HEUCF20111124 and HEUCF101016)the National Basic Research Program of China (Grant No. 2007CB310500)Harbin Key Sci-Tech Project (Grant No. 2010AA4BG004)
文摘Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated. The reflect loss was less than -20 dB for all of the composites in different frequency ranges. The cube-like and walnut-like Fe3O4 composites exhibit improved complex permittivity and permeability and dual-frequency and wide bandwidth absorption characteristics, which is mainly attributed to the larger shape anisotropy. Such a high absorption property indicates that these porous Fe3O4 particles with various morphologies are very promising for electromagnetic wave absorptive materials.
