The structural phase transitions and ferroelectric dynamics of lead-free AgNbO_(3)have attracted consid-erable attention owing to their potential in energy-storage device applications.Here,we examine the impact of Li+...The structural phase transitions and ferroelectric dynamics of lead-free AgNbO_(3)have attracted consid-erable attention owing to their potential in energy-storage device applications.Here,we examine the impact of Li+doping on the phase transitions and polarization behavior of(Ag_(1-x)Li_(x))NbO_(3)(x=0-7%)ceramics through comprehensive dielectric and ferroelectric analyses.Rietveld refinement reveals a Li+-induced phase transition from Pbcm to R3c,with x=5%and x=6%compositions near the morphotropic phase boundary(MPB).Dielectric anomalies identify key characteristic temperatures,supporting the con-struction of a low-field phase diagram.High-field studies uncover a direct relationship between phase structure and polarization behavior,culminating in a high-field phase diagram.Near-MPB compositions exhibit distinct structural states,elucidating the mechanisms of reversible and irreversible phase transi-tions.This work provides a comprehensive explanation of the evolution of hysteresis loop profiles,capturing their progression from double hysteresis loops to square loops and their subsequent reversion to double loops under varying electric field and temperature conditions.These temperature-composition(T-x)and temperature-electric field(T-E)phase diagrams provide a robust framework for understanding phase evolution,offering critical insights into optimizing AgNbO_(3)-based ceramics for advanced functional applications.展开更多
Recently,a plasma catalyst was employed to efflciently degrade antibiotic residues in the environment.In this study,the plasma generated in a packed bed dielectric barrier reactor combined with TiO_(2)catalyst is used...Recently,a plasma catalyst was employed to efflciently degrade antibiotic residues in the environment.In this study,the plasma generated in a packed bed dielectric barrier reactor combined with TiO_(2)catalyst is used to degrade the antibiotic tiamulin(TIA)loaded on the surface of simulated soil particles.The effects of applied voltage,composition of the working gas,gas flow rate and presence or absence of catalyst on the degradation effect were studied.It was found that plasma and catalyst can produce a synergistic effect under optimal conditions(applied voltage 25 k V,oxygen ratio 1%,gas flow rate 0.6 l min^(-1),treatment time 5 min).The degradation efflciency of the plasma combined with catalyst can reach 78.6%,which is 18.4%higher than that of plasma without catalyst.When the applied voltage is 30 k V,the gas flow rate is 1 l min^(-1),the oxygen ratio is 1%and the plasma combined with TiO_(2)catalyst treats the sample for 5 min the degradation efflciency of TIA reached 97%.It can be concluded that a higher applied voltage and longer processing times not only lead to more degradation but also result in a lower energy efflciency.Decreasing the oxygen ratio and gas flow rate could improve the degradation efflciency.The relative distribution and identity of the major TIA degradation product generated was determined by high-performance liquid chromatography–mass spectrometry analysis.The mechanism of TIA removal by plasma and TiO_(2)catalyst was analyzed,and the possible degradation path is discussed.展开更多
The reported electrocaloric(EC)effect in ferroelectrics is poised for application in the next generation of solidstate refrigeration technology,exhibiting substantial developmental potential.This study introduces a no...The reported electrocaloric(EC)effect in ferroelectrics is poised for application in the next generation of solidstate refrigeration technology,exhibiting substantial developmental potential.This study introduces a novel and efficient EC effect strategy in(1-x)Pb(Lu_(1/2)Nb_(1/2))O_(3)-xPbTiO_(3)(PLN-xPT)ceramics for low electric-fielddriven devices.Phase-field simulations provide fundamental insights into thermally induced continuous phase transitions,guiding subsequent experimental investigations.A comprehensive composition/temperature-driven phase evolution diagram is constructed,elucidating the sequential transformation from ferroelectric(FE)to antiferroelectric(AFE)and finally to paraelectric(PE)phases for x=0.10-0.18 components.Direct measurements of EC performance highlight x=0.16 as an outstanding performer,exhibiting remarkable properties,including an adiabatic temperature change(ΔT)of 3.03 K,EC strength(ΔT/ΔE)of 0.08 K cm kV-1,and a temperature span(Tspan)of 31℃.The superior EC effect performance is attributed to the temperature-induced FE to AFE transition at low electric fields and diffusion phase transition behavior contributing to the wide Tspan.This work provides valuable insights into developing high-performance EC effect across broad temperature ranges through the strategic design of continuous phase transitions,offering a simplified and economical approach for advancing ecofriendly and efficient solid-state cooling technologies.展开更多
基金finically supported by the National Natural Science Foundation of China(Nos.52261135548,52302153,and 52402155)the China Postdoctoral Science Foundation(Nos.GZC20232075 and 2023M742767)+2 种基金The research was made possible by Russian Science Foundation(Project No 23-42-00116)The equipment of the Ural Center for Shared Use“Modern nanotech-nology”Ural Federal University(Reg.No2968)whichis supported by the Ministry of Science and Higher Education RF(Project No 075-15-2021-677)was usedThe SEM work was done at International Center for Dielectric Research(ICDR),Xi’an Jiaotong University,Xi’an,China.
文摘The structural phase transitions and ferroelectric dynamics of lead-free AgNbO_(3)have attracted consid-erable attention owing to their potential in energy-storage device applications.Here,we examine the impact of Li+doping on the phase transitions and polarization behavior of(Ag_(1-x)Li_(x))NbO_(3)(x=0-7%)ceramics through comprehensive dielectric and ferroelectric analyses.Rietveld refinement reveals a Li+-induced phase transition from Pbcm to R3c,with x=5%and x=6%compositions near the morphotropic phase boundary(MPB).Dielectric anomalies identify key characteristic temperatures,supporting the con-struction of a low-field phase diagram.High-field studies uncover a direct relationship between phase structure and polarization behavior,culminating in a high-field phase diagram.Near-MPB compositions exhibit distinct structural states,elucidating the mechanisms of reversible and irreversible phase transi-tions.This work provides a comprehensive explanation of the evolution of hysteresis loop profiles,capturing their progression from double hysteresis loops to square loops and their subsequent reversion to double loops under varying electric field and temperature conditions.These temperature-composition(T-x)and temperature-electric field(T-E)phase diagrams provide a robust framework for understanding phase evolution,offering critical insights into optimizing AgNbO_(3)-based ceramics for advanced functional applications.
基金supported by National Natural Science Foundation of China(Nos.51967018,11965018 and 51967017)the Science and Technology Development Fund of Xinjiang Production and Construction(No.2019BC009)the Innovation and Development Special Project of Shihezi University(No.CXFZ202105)。
文摘Recently,a plasma catalyst was employed to efflciently degrade antibiotic residues in the environment.In this study,the plasma generated in a packed bed dielectric barrier reactor combined with TiO_(2)catalyst is used to degrade the antibiotic tiamulin(TIA)loaded on the surface of simulated soil particles.The effects of applied voltage,composition of the working gas,gas flow rate and presence or absence of catalyst on the degradation effect were studied.It was found that plasma and catalyst can produce a synergistic effect under optimal conditions(applied voltage 25 k V,oxygen ratio 1%,gas flow rate 0.6 l min^(-1),treatment time 5 min).The degradation efflciency of the plasma combined with catalyst can reach 78.6%,which is 18.4%higher than that of plasma without catalyst.When the applied voltage is 30 k V,the gas flow rate is 1 l min^(-1),the oxygen ratio is 1%and the plasma combined with TiO_(2)catalyst treats the sample for 5 min the degradation efflciency of TIA reached 97%.It can be concluded that a higher applied voltage and longer processing times not only lead to more degradation but also result in a lower energy efflciency.Decreasing the oxygen ratio and gas flow rate could improve the degradation efflciency.The relative distribution and identity of the major TIA degradation product generated was determined by high-performance liquid chromatography–mass spectrometry analysis.The mechanism of TIA removal by plasma and TiO_(2)catalyst was analyzed,and the possible degradation path is discussed.
基金financially supported by the National Natural Science Foundation of China(Grant No.52261135548)the Key Research and Development Program of Shaanxi(Program No.2022KWZ-22)+2 种基金The research was made possible by Russian Science Foundation(Project No.23-42-00116)The equipment of the Ural Center for Shared Use“Modern nanotechnology”Ural Federal University(Reg.No.2968)which is supported by the Ministry of ScienceHigher Education RF(Project No.075-15-2021-677)was used.
文摘The reported electrocaloric(EC)effect in ferroelectrics is poised for application in the next generation of solidstate refrigeration technology,exhibiting substantial developmental potential.This study introduces a novel and efficient EC effect strategy in(1-x)Pb(Lu_(1/2)Nb_(1/2))O_(3)-xPbTiO_(3)(PLN-xPT)ceramics for low electric-fielddriven devices.Phase-field simulations provide fundamental insights into thermally induced continuous phase transitions,guiding subsequent experimental investigations.A comprehensive composition/temperature-driven phase evolution diagram is constructed,elucidating the sequential transformation from ferroelectric(FE)to antiferroelectric(AFE)and finally to paraelectric(PE)phases for x=0.10-0.18 components.Direct measurements of EC performance highlight x=0.16 as an outstanding performer,exhibiting remarkable properties,including an adiabatic temperature change(ΔT)of 3.03 K,EC strength(ΔT/ΔE)of 0.08 K cm kV-1,and a temperature span(Tspan)of 31℃.The superior EC effect performance is attributed to the temperature-induced FE to AFE transition at low electric fields and diffusion phase transition behavior contributing to the wide Tspan.This work provides valuable insights into developing high-performance EC effect across broad temperature ranges through the strategic design of continuous phase transitions,offering a simplified and economical approach for advancing ecofriendly and efficient solid-state cooling technologies.
