To achieve excellent electromagnetic wave(EMW)absorption properties,the microstructure design of the absorber is critical.In this work,six kinds of N-Ni/C nanostructures with different morphologies were prepared by on...To achieve excellent electromagnetic wave(EMW)absorption properties,the microstructure design of the absorber is critical.In this work,six kinds of N-Ni/C nanostructures with different morphologies were prepared by one-step hydrothermal method and high temperature carbonization by adjusting the types of nickel salts and reaction solvents.The EMW absorption performance of six different morphologies of N-Ni/C nanostructures was compared and analyzed.Among them,it is found that the nanoflowerlike N-Ni/C composite has excellent dielectric loss and magnetic loss synergistic effect due to its polycrystalline structure,and can obtain excellent EMW absorption performance.The minimum reflection loss value at a thickness of 1.9 mm is-59.56 dB at 16.88 GHz,and the effective absorption bandwidth value reaches 6.0 GHz at a thickness of 2.2 mm.Our research shows that different morphologies and multiple lattice structures of nanostructures with the same composition have a significant influence on EMW absorption performance,which provides new research ideas for developing high-performance EMW absorbing materials.展开更多
Confronted with severe electromagnetic wave pollution,the development of high-performance electromagnetic wave shielding or absorbing materials is an effective way to deal with it.Notably,double transition metal alloy...Confronted with severe electromagnetic wave pollution,the development of high-performance electromagnetic wave shielding or absorbing materials is an effective way to deal with it.Notably,double transition metal alloys and transition metal dichalcogenides have attracted extensive attention in electromagnetic wave absorption,but few reports have studied the effects of these two materials on electromagnetic wave absorption at the same time.In this work,cobalt-based alloy with magnetic loss mechanism was selected for composition optimization.The ternary metal-organic framework was prepared by the one-step method,and then CoCu/C was prepared by high temperature annealing.Finally,in the hydrothermal process,ultra-thin tungsten selenide nanosheets were coated on the surface of magnetic component,and the final polyhedral WSe_(2)/CoCu/C composites with multiple heterogeneous interfaces were obtained.The synergistic effect of dielectric and magnetic components optimizes impedance matching and allows more electromagnetic waves to enter the absorber.Subsequently,through the conduction loss of high conductivity graphitized carbon,interfacial polarization,and dipole polarization of heterogeneous interfaces between the components,the magnetic loss provided by CoCu alloy can work together to maximize the attenuation ability of electromagnetic waves.Exactly,the minimum reflection loss(RLmin)value of the composite reaches-53.43 dB when the matched thickness is 2.1 mm,while the maximum effective absorption bandwidth(EABmax)reaches 6.0 GHz at a thin thickness of 1.8 mm.This work provides some support and reference for the design of novel electromagnetic wave absorbing materials via the dielectric/magnetic loss synergistic mechanism.展开更多
Electronic devices pervade everyday life,which has triggered severe electromagnetic(EM)wave pollution.To face this challenge,developing EM wave absorbers with ultra-broadband absorption capacity is critically required...Electronic devices pervade everyday life,which has triggered severe electromagnetic(EM)wave pollution.To face this challenge,developing EM wave absorbers with ultra-broadband absorption capacity is critically required.Currently,nano-composite construction has been widely utilized to realize impedance match and broadband absorption.However,complex experimental procedures,limited thermal stability,and interior oxidation resistance are still unneglectable issues.Therefore,it is appealing to realize ultra-broadband EM wave absorption in single-phase materials with good stability.Aiming at this target,two high-entropy transition metal carbides(HE TMCs)including(Zr,Hf,Nb,Ta)C(HE TMC-2)and(Cr,Zr,Hf,Nb,Ta)C(HE TMC-3)are designed and synthesized,of which the microwave absorption performance is investigated in comparison with previously reported(Ti,Zr,Hf,Nb,Ta)C(HE TMC-1).Due to the synergistic effects of dielectric and magnetic losses,HE TMC-2 and HE TMC-3 exhibit better impedance match and wider effective absorption bandwidth(EAB).In specific,the exclusion of Ti element in HE TMC-2 endows it optimal minimum reflection loss(RL_(min))and EAB of−41.7 dB(2.11 mm,10.52 GHz)and 3.5 GHz(at 3.0 mm),respectively.Remarkably,the incorporation of Cr element in HE TMC-3 significantly improves the impedance match,thus realizing EAB of 10.5,9.2,and 13.9 GHz at 2,3,and 4 mm,respectively.The significance of this study lays on realizing ultra-broadband capacity in HE TMC-3(Cr,Zr,Hf,Nb,Ta),demonstrating the effectiveness of high-entropy component design in tailoring the impedance match.展开更多
Growing electromagnetic pollution has plagued researchers in the field of electromagnetic(EM)energy dissipation for many years;it is increasingly important to solve this problem efficiently.Metal-organic frameworks(MO...Growing electromagnetic pollution has plagued researchers in the field of electromagnetic(EM)energy dissipation for many years;it is increasingly important to solve this problem efficiently.Metal-organic frameworks(MOFs),a shining star of functional materials,have attracted great attention for their advantages,which include highly tunable porosity,structure,and versatility.MOF-derived electromagnetic wave(EMW)absorbers,with advantages such as light weight,thin matching thickness,strong capacity,and wide effective bandwidth,are widely reported.However,current studies lack a systematic summary of the ternary synergistic effects of the precursor component-structure-EMW absorption behavior of MOF derivatives.Here we describe in detail the electromagnetic(EM)energy dissipation mechanism and strategy for preparing MOF-derived EMW absorbers.On the basis of this description,the following means are suggested for adjusting the EM parameters of MOF derivatives,achieving excellent EM energy dissipation:(1)changing the metal and ligands to regulate the chemical composition and morphology of the precursor,(2)controlling pyrolysis parameters(including temperature,heating rate,and gas atmosphere)to manipulate the structure and components of derivatives,and(3)compounding with enhancement phases,including carbon nanomaterials,metals,or other MOFs.展开更多
The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution.To cope with this challenge,exploring high-performance electromagnetic(EM)wave absorbing materials with dielect...The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution.To cope with this challenge,exploring high-performance electromagnetic(EM)wave absorbing materials with dielectric and magnetic losses coupling is urgently required.Of the EM wave absorbers,transition metal diborides(TMB2)possess excellent dielectric loss capability.However,akin to other single dielectric materials,poor impedance match leads to inferior performance.High-entropy engineering is expected to be effective in tailoring the balance between dielectric and magnetic losses through compositional design.Herein,three HE TMB2 powders with nominal equimolar TM including HE TMB2-I(TM=Zr,Hf,Nb,Ta),HE TMB2-2(TM=Ti,Zr,Hf,Nb,Ta),and HE TMB2-3(TM=Cr,Zr,Hf,Nb,Ta)have been designed and prepared by one-step boro/carbothermal reduction.As a result of synergistic effects of strong attenuation capability and impedance match,HE TMB2-1 shows much improved performance with the optimal minimum reflection loss(RL_(min))of-59.6 dB(8.48 GHz,2.68 mm)and effective absorption bandwidth(EAB)of 7.6 GHz(2.3 mm).Most impressively,incorporating Cr in HE TMB2-3 greatly improves the impedance match over 1-18 GHz,thus achieving the RLmin of-56.2 dB(8.48 GHz,2.63 mm)and the EAB of 11.0 GHz(2.2 mm),which is superior to most other EM wave absorbing materials.This work reveals that constructing high-entropy compounds,especially by incorporating magnetic elements,is effectual in tailoring the impedance match for highly conductive compounds,i.e.,tuning electrical conductivity and boosting magnetic loss to realize highly efficient and broadband EM wave absorption with dielectric and magnetic coupling in single-phase materials.展开更多
Due to the temperature and frequency response of electromagnetic(EM)loss,how to realize the effective design of microwave absorption materials(MWAMs)at elevated temperature is highly desirable for practical applicatio...Due to the temperature and frequency response of electromagnetic(EM)loss,how to realize the effective design of microwave absorption materials(MWAMs)at elevated temperature is highly desirable for practical applications.Herein,transition metaldoped titanium nitride(M-TiN,M=Fe or Co)fibers were fabricated,the distortion of TiN lattice could cause the adjustable charge enrichment,which played a profound influence on the dielectric response and EM microwave absorption(EMWA)performances.Benefiting from the negative correlation between dielectric loss and temperature,more loss mechanism could be introduced,which would effectively enhance dielectric loss and EMWA performances at elevated temperature.The optimal EMWA performances of Fe-TiN fibers/polydimethylsiloxane(PDMS)composites were realized with a wide temperature range(298–423 K):the reflection loss(RL)could reach 99%(RL<−20 dB)at 12.2 GHz with 1.8 mm,when the filler content was only 15.0 wt.%.Compared with the undoped-TiN fibers/PDMS and Co-TiN fibers/PDMS composites,the excellent EMWA of Fe-TiN fibers/PDMS composite could be attributed to the reasonably synergistic polarization loss and conduction loss.Based on systematic analysis of the variable-temperature EM parameters and EMWA performances,the optimization of EMWA performances in wide temperature domain could be realized by introducing appropriate polarization loss and its compensating.Hopefully,this work provides a new strategy for regulating the dielectric response and designing effective MWAMs at elevated temperature.展开更多
Maximizing the energy-loading performance of gratings is a universal theme in high-energy pulse compression.However,sporadic grating designs strongly restrict the development of high-power laser engineering.This study...Maximizing the energy-loading performance of gratings is a universal theme in high-energy pulse compression.However,sporadic grating designs strongly restrict the development of high-power laser engineering.This study proposes an all-and mixed-dielectric grating design paradigm for Nd:glass-based pulse compressors.The solution regions are classified according to the line density.High diffraction efficiency solutions are described in more detail based on the dispersion amount and incident angle.Moreover,an energy scaling factor of 7.09 times larger than that of the National Ignition Facility’s Advanced Radiographic Capability(NIF-ARC)is obtained by taking advantage of the low electric field intensity at transverse magnetic polarization and a small incident angle.These results make a pioneering contribution to facilitate future 20–50-petawatt-class ultrafast laser systems.展开更多
Composites composed of a carbon matrix decorated with a metal or metal oxide derived from zeolitic imidazolate frameworks(ZIFs)have been widely applied as suitable electromagnetic wave absorbers due to their high poro...Composites composed of a carbon matrix decorated with a metal or metal oxide derived from zeolitic imidazolate frameworks(ZIFs)have been widely applied as suitable electromagnetic wave absorbers due to their high porosity and controllable morphology.However,achieving ideal absorption performance remains a challenge owing to the inadequate conductivity and high density of the metal components.Therefore,a temperature-controlling treatment was employed for the bimetal ZIFs,and the corresponding derivatives exhibited an excellent dissipation ability with a minimum reflection loss value of−54.3 dB and an effective bandwidth of 7.0 GHz at a thickness of 2.4 mm,which resulted from the strong dipole polarization behavior.Furthermore,after successfully controlling the Zn/Co ratio,the attenuation capability was greatly enhanced at a thickness of 1.4 mm,with bandwidths of 13.0–18.0 GHz.Overall,this work provides an ameliorated strategy for microwave absorption performance of carbon-based materials.展开更多
We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals（MDPhCs） with hexagonal arrays of subwavelength...We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals（MDPhCs） with hexagonal arrays of subwavelength holes in gold/silicon dioxide films,varying the array periodicity from 6 to 8μm every 1μm while the ratio of hole radius to array periodicity is kept constant（1/4）.The results indicate that the reflectance spectrum is highly dependent on the array periodicity.When the array periodicity increases,the reflectance spectrum exhibits a large redshift regularly.The finite difference time domain（FDTD） simulations agree well with the experimental results. By analyzing the relationship between the position of the reflectance minimum and the array periodicity,we find that the filtering characteristics of MDPhCs have an almost linear relationship with the array periodicity under the conditions of keeping the same ratio of hole radius to array periodicity（1/4）.This finding provides an effective way to control the filtering characteristics of MDPhCs,which have potential applications in optical filters,plasmonic thermal emitters and so on.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51407134 and 52002196)the Natural Science Foundation of Shandong Province(Nos.ZR2019YQ24 and ZR2020QF084)+2 种基金the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)the Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams(No.37000022P990304116449)).
文摘To achieve excellent electromagnetic wave(EMW)absorption properties,the microstructure design of the absorber is critical.In this work,six kinds of N-Ni/C nanostructures with different morphologies were prepared by one-step hydrothermal method and high temperature carbonization by adjusting the types of nickel salts and reaction solvents.The EMW absorption performance of six different morphologies of N-Ni/C nanostructures was compared and analyzed.Among them,it is found that the nanoflowerlike N-Ni/C composite has excellent dielectric loss and magnetic loss synergistic effect due to its polycrystalline structure,and can obtain excellent EMW absorption performance.The minimum reflection loss value at a thickness of 1.9 mm is-59.56 dB at 16.88 GHz,and the effective absorption bandwidth value reaches 6.0 GHz at a thickness of 2.2 mm.Our research shows that different morphologies and multiple lattice structures of nanostructures with the same composition have a significant influence on EMW absorption performance,which provides new research ideas for developing high-performance EMW absorbing materials.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+4 种基金the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)the Key Laboratory of Engineering Dielectrics and Its Application(Harbin University of Science and Technology)the Ministry of Educationthe Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams).
文摘Confronted with severe electromagnetic wave pollution,the development of high-performance electromagnetic wave shielding or absorbing materials is an effective way to deal with it.Notably,double transition metal alloys and transition metal dichalcogenides have attracted extensive attention in electromagnetic wave absorption,but few reports have studied the effects of these two materials on electromagnetic wave absorption at the same time.In this work,cobalt-based alloy with magnetic loss mechanism was selected for composition optimization.The ternary metal-organic framework was prepared by the one-step method,and then CoCu/C was prepared by high temperature annealing.Finally,in the hydrothermal process,ultra-thin tungsten selenide nanosheets were coated on the surface of magnetic component,and the final polyhedral WSe_(2)/CoCu/C composites with multiple heterogeneous interfaces were obtained.The synergistic effect of dielectric and magnetic components optimizes impedance matching and allows more electromagnetic waves to enter the absorber.Subsequently,through the conduction loss of high conductivity graphitized carbon,interfacial polarization,and dipole polarization of heterogeneous interfaces between the components,the magnetic loss provided by CoCu alloy can work together to maximize the attenuation ability of electromagnetic waves.Exactly,the minimum reflection loss(RLmin)value of the composite reaches-53.43 dB when the matched thickness is 2.1 mm,while the maximum effective absorption bandwidth(EABmax)reaches 6.0 GHz at a thin thickness of 1.8 mm.This work provides some support and reference for the design of novel electromagnetic wave absorbing materials via the dielectric/magnetic loss synergistic mechanism.
基金We gratefully acknowledge the financial support from the National Natural Science Foundation of China(Nos.51972089,51672064,and U1435206).
文摘Electronic devices pervade everyday life,which has triggered severe electromagnetic(EM)wave pollution.To face this challenge,developing EM wave absorbers with ultra-broadband absorption capacity is critically required.Currently,nano-composite construction has been widely utilized to realize impedance match and broadband absorption.However,complex experimental procedures,limited thermal stability,and interior oxidation resistance are still unneglectable issues.Therefore,it is appealing to realize ultra-broadband EM wave absorption in single-phase materials with good stability.Aiming at this target,two high-entropy transition metal carbides(HE TMCs)including(Zr,Hf,Nb,Ta)C(HE TMC-2)and(Cr,Zr,Hf,Nb,Ta)C(HE TMC-3)are designed and synthesized,of which the microwave absorption performance is investigated in comparison with previously reported(Ti,Zr,Hf,Nb,Ta)C(HE TMC-1).Due to the synergistic effects of dielectric and magnetic losses,HE TMC-2 and HE TMC-3 exhibit better impedance match and wider effective absorption bandwidth(EAB).In specific,the exclusion of Ti element in HE TMC-2 endows it optimal minimum reflection loss(RL_(min))and EAB of−41.7 dB(2.11 mm,10.52 GHz)and 3.5 GHz(at 3.0 mm),respectively.Remarkably,the incorporation of Cr element in HE TMC-3 significantly improves the impedance match,thus realizing EAB of 10.5,9.2,and 13.9 GHz at 2,3,and 4 mm,respectively.The significance of this study lays on realizing ultra-broadband capacity in HE TMC-3(Cr,Zr,Hf,Nb,Ta),demonstrating the effectiveness of high-entropy component design in tailoring the impedance match.
基金financially supported by the Natural Science Foundation of Jiangsu Province(No.BK20221336)the Jiangsu Agricultural Science and Technology Independent Innovation Fund(No.CX(20)3041)+2 种基金the National Natural Science Foundation of China(No.31971740)the Research Project of the Jiangxi Forestry Bureau(No.202134)the Nanping Science and Technology Planning Project(No.2020Z001)。
文摘Growing electromagnetic pollution has plagued researchers in the field of electromagnetic(EM)energy dissipation for many years;it is increasingly important to solve this problem efficiently.Metal-organic frameworks(MOFs),a shining star of functional materials,have attracted great attention for their advantages,which include highly tunable porosity,structure,and versatility.MOF-derived electromagnetic wave(EMW)absorbers,with advantages such as light weight,thin matching thickness,strong capacity,and wide effective bandwidth,are widely reported.However,current studies lack a systematic summary of the ternary synergistic effects of the precursor component-structure-EMW absorption behavior of MOF derivatives.Here we describe in detail the electromagnetic(EM)energy dissipation mechanism and strategy for preparing MOF-derived EMW absorbers.On the basis of this description,the following means are suggested for adjusting the EM parameters of MOF derivatives,achieving excellent EM energy dissipation:(1)changing the metal and ligands to regulate the chemical composition and morphology of the precursor,(2)controlling pyrolysis parameters(including temperature,heating rate,and gas atmosphere)to manipulate the structure and components of derivatives,and(3)compounding with enhancement phases,including carbon nanomaterials,metals,or other MOFs.
基金supports from the National Natural Science Foundation of China(Grant Nos.51972089,51672064,and U1435206).
文摘The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution.To cope with this challenge,exploring high-performance electromagnetic(EM)wave absorbing materials with dielectric and magnetic losses coupling is urgently required.Of the EM wave absorbers,transition metal diborides(TMB2)possess excellent dielectric loss capability.However,akin to other single dielectric materials,poor impedance match leads to inferior performance.High-entropy engineering is expected to be effective in tailoring the balance between dielectric and magnetic losses through compositional design.Herein,three HE TMB2 powders with nominal equimolar TM including HE TMB2-I(TM=Zr,Hf,Nb,Ta),HE TMB2-2(TM=Ti,Zr,Hf,Nb,Ta),and HE TMB2-3(TM=Cr,Zr,Hf,Nb,Ta)have been designed and prepared by one-step boro/carbothermal reduction.As a result of synergistic effects of strong attenuation capability and impedance match,HE TMB2-1 shows much improved performance with the optimal minimum reflection loss(RL_(min))of-59.6 dB(8.48 GHz,2.68 mm)and effective absorption bandwidth(EAB)of 7.6 GHz(2.3 mm).Most impressively,incorporating Cr in HE TMB2-3 greatly improves the impedance match over 1-18 GHz,thus achieving the RLmin of-56.2 dB(8.48 GHz,2.63 mm)and the EAB of 11.0 GHz(2.2 mm),which is superior to most other EM wave absorbing materials.This work reveals that constructing high-entropy compounds,especially by incorporating magnetic elements,is effectual in tailoring the impedance match for highly conductive compounds,i.e.,tuning electrical conductivity and boosting magnetic loss to realize highly efficient and broadband EM wave absorption with dielectric and magnetic coupling in single-phase materials.
基金support of the National Nature Science Foundation of China(No.U1704253)the Key Scientific Research Project Plan in Universities of Henan Province(No.23A430037)the Science and Technology Planning Project of Henan Province(No.212102210474).
文摘Due to the temperature and frequency response of electromagnetic(EM)loss,how to realize the effective design of microwave absorption materials(MWAMs)at elevated temperature is highly desirable for practical applications.Herein,transition metaldoped titanium nitride(M-TiN,M=Fe or Co)fibers were fabricated,the distortion of TiN lattice could cause the adjustable charge enrichment,which played a profound influence on the dielectric response and EM microwave absorption(EMWA)performances.Benefiting from the negative correlation between dielectric loss and temperature,more loss mechanism could be introduced,which would effectively enhance dielectric loss and EMWA performances at elevated temperature.The optimal EMWA performances of Fe-TiN fibers/polydimethylsiloxane(PDMS)composites were realized with a wide temperature range(298–423 K):the reflection loss(RL)could reach 99%(RL<−20 dB)at 12.2 GHz with 1.8 mm,when the filler content was only 15.0 wt.%.Compared with the undoped-TiN fibers/PDMS and Co-TiN fibers/PDMS composites,the excellent EMWA of Fe-TiN fibers/PDMS composite could be attributed to the reasonably synergistic polarization loss and conduction loss.Based on systematic analysis of the variable-temperature EM parameters and EMWA performances,the optimization of EMWA performances in wide temperature domain could be realized by introducing appropriate polarization loss and its compensating.Hopefully,this work provides a new strategy for regulating the dielectric response and designing effective MWAMs at elevated temperature.
基金This work was supported by the National Key R&D Program of China(No.2020YFA0714500)the National Natural Science Foundation of China(Nos.61875212 and U1831211)+2 种基金the Shanghai Strategic Emerging Industry Development Special Fund(No.31011442501217020191D3101001)the International Partnership Program of Chinese Academy of Sciences(No.181231KYSB20200040)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA25020314).
文摘Maximizing the energy-loading performance of gratings is a universal theme in high-energy pulse compression.However,sporadic grating designs strongly restrict the development of high-power laser engineering.This study proposes an all-and mixed-dielectric grating design paradigm for Nd:glass-based pulse compressors.The solution regions are classified according to the line density.High diffraction efficiency solutions are described in more detail based on the dispersion amount and incident angle.Moreover,an energy scaling factor of 7.09 times larger than that of the National Ignition Facility’s Advanced Radiographic Capability(NIF-ARC)is obtained by taking advantage of the low electric field intensity at transverse magnetic polarization and a small incident angle.These results make a pioneering contribution to facilitate future 20–50-petawatt-class ultrafast laser systems.
基金The authors are thankful for the financial supports of the Science Foundation for The Excellent Youth Scholars of Henan Province(No.212300410089)the Foundation for University Youth Key Teachers of Henan Province(No.2020GGJS170)the Support Program for Scientific and Technological Innovation Talents of Higher Education in Henan Province(No.21HASTIT004).
文摘Composites composed of a carbon matrix decorated with a metal or metal oxide derived from zeolitic imidazolate frameworks(ZIFs)have been widely applied as suitable electromagnetic wave absorbers due to their high porosity and controllable morphology.However,achieving ideal absorption performance remains a challenge owing to the inadequate conductivity and high density of the metal components.Therefore,a temperature-controlling treatment was employed for the bimetal ZIFs,and the corresponding derivatives exhibited an excellent dissipation ability with a minimum reflection loss value of−54.3 dB and an effective bandwidth of 7.0 GHz at a thickness of 2.4 mm,which resulted from the strong dipole polarization behavior.Furthermore,after successfully controlling the Zn/Co ratio,the attenuation capability was greatly enhanced at a thickness of 1.4 mm,with bandwidths of 13.0–18.0 GHz.Overall,this work provides an ameliorated strategy for microwave absorption performance of carbon-based materials.
文摘We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals（MDPhCs） with hexagonal arrays of subwavelength holes in gold/silicon dioxide films,varying the array periodicity from 6 to 8μm every 1μm while the ratio of hole radius to array periodicity is kept constant（1/4）.The results indicate that the reflectance spectrum is highly dependent on the array periodicity.When the array periodicity increases,the reflectance spectrum exhibits a large redshift regularly.The finite difference time domain（FDTD） simulations agree well with the experimental results. By analyzing the relationship between the position of the reflectance minimum and the array periodicity,we find that the filtering characteristics of MDPhCs have an almost linear relationship with the array periodicity under the conditions of keeping the same ratio of hole radius to array periodicity（1/4）.This finding provides an effective way to control the filtering characteristics of MDPhCs,which have potential applications in optical filters,plasmonic thermal emitters and so on.
