In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The...In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).展开更多
A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern f...A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern for their utilization as an electricity generator in day-to-day life.Herein,we proposed a lead-free silver niobate(AgNbO_(3)(ANb))microparticles(MPs)-embedded polydimethylsiloxane(PDMS)composite film-based clip-like hybrid nanogenerator(HNG)device,producing an enhanced electrical output from the applied mechanical movements.The ANb MPs with a high dielectric constant were initially synthesized and embedded inside the PDMS polymer matrix.Various HNGs were fabricated utilizing ANb MPs/PDMS composite films/aluminum tape as negative/positive triboelectric films,respectively and operated in contact-separation mode.The electrical output from them was comparatively analyzed to investigate an optimum concentration of the ANb MPs inside the PDMS film.The robust HNG with 5 wt%ANb MPs/PDMS composite film produced the highest electrical output with promising stability.Thereafter,three similar optimized HNGs were fabricated and integrated within a 3D-printed clip-like structure and the electrical output was thoroughly evaluated while combining multiple HNGs as well as from each independent HNG.The clip-like HNG device exhibited an electrical output of 340 V and 20μA that can be further utilized to charge various capacitors and power portable electronics.Owing to the high resilience structure of the clip-like HNG device,it was also demonstrated to harvest biomechanical energy produced by human movements into electricity.The mechanical energy harvesting when the clip-like HNG device was attached to the accelerator pedal of the car and the pedal of a musical piano was successfully demonstrated.展开更多
A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3...A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride (TMC) as organic monomer,thin film composite (TFC) nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na2SO4MgSO4MgCl2NaCl.This sequence indicates that the membranes are negatively charged.展开更多
Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor(VDMOS) devices with composite SiO2-Si3N4 film gates are investigated.The relationships amon...Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor(VDMOS) devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films.展开更多
Nanocellulose has served as an eye-catching nanomaterial for constructing advanced functional devices with renewability,light weight,flexibility,and environmental friendliness.In this study,Co_(3)O_(4)/graphene/cellul...Nanocellulose has served as an eye-catching nanomaterial for constructing advanced functional devices with renewability,light weight,flexibility,and environmental friendliness.In this study,Co_(3)O_(4)/graphene/cellulose nanofiber(CNF)flexible composite films,in which the CNF acted as a spacer for the graphene,were prepared via a facile and scalable vacuum filtration method.The effects of the CNF on the microstructure,hydrophilicity,thermal stability,tensile strength,surface resistance,and electrochemical performance of the Co_(3)O_(4)/graphene/CNF composite films were systematically investigated.The results showed that the synergistic interaction of the CNF and graphene substantially improved the overall properties of the Co_(3)O_(4)/graphene/CNF composite films,particularly their hydrophilicity and tensile strength.Meanwhile,Co_(3)O_(4)/graphene/CNF composite films with a CNF content of 4%appeared to have the optimal electrochemical performance,with an area specific capacitance of 56 mF/cm^(2) and prominent capacitance retention of 95.6%at a current density of 1 A/g after 1000 cycles.This work demonstrated that the prepared Co_(3)O_(4)/graphene/CNF flexible composite films have great application potential in the field of flexible energy storage devices.展开更多
The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an en...The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.展开更多
Titanium dioxide (TiO2) loaded tungsten trioxide (WO3) composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-...Titanium dioxide (TiO2) loaded tungsten trioxide (WO3) composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers' separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.展开更多
With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared...With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared by spin-coating method. Structural, electrical and optical characterization showed that rGO-P3HT films 9.0 wt% P3HT exhibited good stability when exposed to the ambient atmosphere. These composite films of 200 nm thickness possess a sheet resistance and transparency of R□~ 17Ω and T ~ 72%, respectively. Owing to containing conducting polymer, rGO-P3HT-coated glass could be efficiently used in photovoltaic applications, in organic solar cells in particular, with the replacement of the indium tin oxide (ITO) and fluorine tin oxide (FTO) electrodes.展开更多
Biopolymers,the potential flexoelectric materials,are environment-friendly,degradable,lightweight,cost-effective,and possess remarkable processing properties catering to the requirements of advanced devices.However,th...Biopolymers,the potential flexoelectric materials,are environment-friendly,degradable,lightweight,cost-effective,and possess remarkable processing properties catering to the requirements of advanced devices.However,the flexoelectric coefficient of biopolymers is normally much weaker than that of ceramic materials,limiting their potential applications for designing high-performance green electromechanical coupling devices.To improve the flexoelectric response in biopolymers,we composited barium titanate(BTO)with 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibrils(TOCNF)to enhance the flexoelectric response of TOCNF.Owing to the high permittivity and flexoelectric effect of BTO,the relative dielectric constant and flexoelectric coefficient of 33.3 wt%BTO-TOCNF films reached 30.94@1 kHz and 50.05±1.88 nC/m@1 Hz,which were almost 172 times and 27 times higher than those of TOCNF,respectively.The composite thin film contains high dielectric constant and flexoelectric coefficient,as well as excellent flexibility.Our study provided a straightforward and efficient method for improving the flexoelectric effect of biopolymers,and demonstrated its great potential applications in flexoelectric-based devices.展开更多
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
A Ba_(0.8)Sr_(0.2)TiO_(3)/CoFe_(2)O_(4)layered heterostructure film was grown on a Pt/TiO_(2)/SiO_(2)/Si substrate by rf-magnetron sputtering.X-ray diffraction shows that the film consists of perovskite Ba_(0.8)Sr_(0....A Ba_(0.8)Sr_(0.2)TiO_(3)/CoFe_(2)O_(4)layered heterostructure film was grown on a Pt/TiO_(2)/SiO_(2)/Si substrate by rf-magnetron sputtering.X-ray diffraction shows that the film consists of perovskite Ba_(0.8)Sr_(0.2)TiO_(3)and spinel CoFe_(2)O_(4)phases.The microstructures of the film were observed by a scanning electron microscope(SEM),showing good surface morphology and clear interfaces among the Ba_(0.8)Sr_(0.2)TiO_(3)film,the CoFe_(2)O_(4)film and the substrate.The variations of dielectric properties with frequency of the heterostructure film are investigated.The heterostructure film simultaneously displays distinct ferroelectricity and ferromagnetism.Moreover,an obvious magnetoelectric coupling effect was observed in the heterostructure film with a maximum magnetoelectric voltage coefficient of 5.0 mV·cm^(-1)Oe^(-1),which is about seven times larger than that of the Ba_(0.8)Sr_(0.2)TiO_(3)/CoFe_(2)O_(4)particulate composite ceramics in a previous report.展开更多
基金Funded by the Youth Backbone Teacher Training Plan in University of Henan Province(No.21220028)Science and Technology Research Project of Henan Province(No.242102321066)+2 种基金Natural Science Foundation of Henan Province(No.232300420312)Henan University of Technology Young Backbone Teacher Training Plan(No.21421260)the Innovation Training Program for College Students in Henan Province(No.202310463046)。
文摘In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2018R1A6A1A03025708 and No.2020M3H2A1076786).
文摘A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern for their utilization as an electricity generator in day-to-day life.Herein,we proposed a lead-free silver niobate(AgNbO_(3)(ANb))microparticles(MPs)-embedded polydimethylsiloxane(PDMS)composite film-based clip-like hybrid nanogenerator(HNG)device,producing an enhanced electrical output from the applied mechanical movements.The ANb MPs with a high dielectric constant were initially synthesized and embedded inside the PDMS polymer matrix.Various HNGs were fabricated utilizing ANb MPs/PDMS composite films/aluminum tape as negative/positive triboelectric films,respectively and operated in contact-separation mode.The electrical output from them was comparatively analyzed to investigate an optimum concentration of the ANb MPs inside the PDMS film.The robust HNG with 5 wt%ANb MPs/PDMS composite film produced the highest electrical output with promising stability.Thereafter,three similar optimized HNGs were fabricated and integrated within a 3D-printed clip-like structure and the electrical output was thoroughly evaluated while combining multiple HNGs as well as from each independent HNG.The clip-like HNG device exhibited an electrical output of 340 V and 20μA that can be further utilized to charge various capacitors and power portable electronics.Owing to the high resilience structure of the clip-like HNG device,it was also demonstrated to harvest biomechanical energy produced by human movements into electricity.The mechanical energy harvesting when the clip-like HNG device was attached to the accelerator pedal of the car and the pedal of a musical piano was successfully demonstrated.
基金Supported by the National Natural Science Foundation of China(21076176) the Research and Development Project of Tangshan(10140201C-3)+1 种基金 the Research and Development Project of Hebei Province(07275113) the Research Fund of Tangshan Normal College
文摘A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride (TMC) as organic monomer,thin film composite (TFC) nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na2SO4MgSO4MgCl2NaCl.This sequence indicates that the membranes are negatively charged.
文摘Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor(VDMOS) devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films.
基金This work was financially supported by the National Natural Science Foundation of China(grant no.22078306)Key Research and Development Program of Zhejiang Province(grant no.2020C02021)+1 种基金521 Talent Cultivation Program of Zhejiang Sci-Tech University(grant no.11110132521310)Qujiang Science and Technology Project(grant no.QJ2020023).
文摘Nanocellulose has served as an eye-catching nanomaterial for constructing advanced functional devices with renewability,light weight,flexibility,and environmental friendliness.In this study,Co_(3)O_(4)/graphene/cellulose nanofiber(CNF)flexible composite films,in which the CNF acted as a spacer for the graphene,were prepared via a facile and scalable vacuum filtration method.The effects of the CNF on the microstructure,hydrophilicity,thermal stability,tensile strength,surface resistance,and electrochemical performance of the Co_(3)O_(4)/graphene/CNF composite films were systematically investigated.The results showed that the synergistic interaction of the CNF and graphene substantially improved the overall properties of the Co_(3)O_(4)/graphene/CNF composite films,particularly their hydrophilicity and tensile strength.Meanwhile,Co_(3)O_(4)/graphene/CNF composite films with a CNF content of 4%appeared to have the optimal electrochemical performance,with an area specific capacitance of 56 mF/cm^(2) and prominent capacitance retention of 95.6%at a current density of 1 A/g after 1000 cycles.This work demonstrated that the prepared Co_(3)O_(4)/graphene/CNF flexible composite films have great application potential in the field of flexible energy storage devices.
文摘The oxidation behaviors of Fe26Cr1Mo with and without the Ni La 2O 3 electrodeposited composite film have been investigated by thermogravimetric analysis (TGA) and a scanning electron microscope equipped with an energy dispersive analytical X ray system(SEM/EDAX). The experimental results show that the oxide scale growing on Fe26Cr1Mo exposed at 900 ℃ spalled severely during cooling, while after the stainless steel was coated with the Ni La 2O 3 electrodeposited composite film, its high temperature cyclic oxidation resistance was significantly improved. The reason is that a La 2O 3 modified NiO scale, which has a superior adhesion to the substrate, was formed on the Fe26Cr1Mo stainless steel coated with Ni La 2O 3 composite film.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174137,11474215 and 21204058the Natural Science Foundation for the Youth of Jiangsu Province under Grant No BK20130284the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Titanium dioxide (TiO2) loaded tungsten trioxide (WO3) composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers' separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.
文摘With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared by spin-coating method. Structural, electrical and optical characterization showed that rGO-P3HT films 9.0 wt% P3HT exhibited good stability when exposed to the ambient atmosphere. These composite films of 200 nm thickness possess a sheet resistance and transparency of R□~ 17Ω and T ~ 72%, respectively. Owing to containing conducting polymer, rGO-P3HT-coated glass could be efficiently used in photovoltaic applications, in organic solar cells in particular, with the replacement of the indium tin oxide (ITO) and fluorine tin oxide (FTO) electrodes.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272285,12322205,and 12122209)the Young Elite Scientist Sponsorship Program by CAST(Grant No.2019QNRC001)+1 种基金the 1000-Plan Program of Shaanxi Provincethe Young Talent Support Plan of Xi’an Jiaotong University.
文摘Biopolymers,the potential flexoelectric materials,are environment-friendly,degradable,lightweight,cost-effective,and possess remarkable processing properties catering to the requirements of advanced devices.However,the flexoelectric coefficient of biopolymers is normally much weaker than that of ceramic materials,limiting their potential applications for designing high-performance green electromechanical coupling devices.To improve the flexoelectric response in biopolymers,we composited barium titanate(BTO)with 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibrils(TOCNF)to enhance the flexoelectric response of TOCNF.Owing to the high permittivity and flexoelectric effect of BTO,the relative dielectric constant and flexoelectric coefficient of 33.3 wt%BTO-TOCNF films reached 30.94@1 kHz and 50.05±1.88 nC/m@1 Hz,which were almost 172 times and 27 times higher than those of TOCNF,respectively.The composite thin film contains high dielectric constant and flexoelectric coefficient,as well as excellent flexibility.Our study provided a straightforward and efficient method for improving the flexoelectric effect of biopolymers,and demonstrated its great potential applications in flexoelectric-based devices.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
基金the National Natural Science Foundation of China under Grant No 60971008the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 200804870071.
文摘A Ba_(0.8)Sr_(0.2)TiO_(3)/CoFe_(2)O_(4)layered heterostructure film was grown on a Pt/TiO_(2)/SiO_(2)/Si substrate by rf-magnetron sputtering.X-ray diffraction shows that the film consists of perovskite Ba_(0.8)Sr_(0.2)TiO_(3)and spinel CoFe_(2)O_(4)phases.The microstructures of the film were observed by a scanning electron microscope(SEM),showing good surface morphology and clear interfaces among the Ba_(0.8)Sr_(0.2)TiO_(3)film,the CoFe_(2)O_(4)film and the substrate.The variations of dielectric properties with frequency of the heterostructure film are investigated.The heterostructure film simultaneously displays distinct ferroelectricity and ferromagnetism.Moreover,an obvious magnetoelectric coupling effect was observed in the heterostructure film with a maximum magnetoelectric voltage coefficient of 5.0 mV·cm^(-1)Oe^(-1),which is about seven times larger than that of the Ba_(0.8)Sr_(0.2)TiO_(3)/CoFe_(2)O_(4)particulate composite ceramics in a previous report.