Lead halide hybrids are promising switchable dielectric materials owing to their structural tunability,which enables thermotropic phase transitions.However,achieving large dielectric contrasts remains a significant ch...Lead halide hybrids are promising switchable dielectric materials owing to their structural tunability,which enables thermotropic phase transitions.However,achieving large dielectric contrasts remains a significant challenge.Here,we demonstrate a strategy to markedly enhance the dielectric switching ratio(DSR)by engineering a phase-transition compound with elevated ionic conduction in the high-temperature phase via vacancy-enabled ionic transport.Using[C_(5)H_(12)N]_(2)PbCl_(4)(C_(5)H_(12)N^(+)=piperidinium)as a model,we synthesized a series of[C_(5)H_(12)N]_(2)-2xPb_(1-x)Mn_(x)Cl_(4)-2x(x=0.01-0.15)via solvent-free mechanochemistry.Mn^(2+)-doping introduces charge-compensating C_(5)H_(12)N^(+)and Cl-vacancies into the lattice,triggering a structural phase transition.As anticipated,the doped hybrids exhibit a substantially improved DSR,with the x=0.15 composition reaching an ultrahigh value of~10^(3),surpassing most reported dielectric switching materials.This enhancement is attributed to a grain boundary-induced barrier layer mechanism within the ion-conducting system.Our results establish vacancy-enabled ionic transport as a viable strategy for designing high-performance dielectric switching materials within soft halide frameworks.展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the National Nature Science Foundation of China(grant no.22073047)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,the Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,the Suzhou Key Laboratory of Advanced Photonic Materials(Grant SZS_(2)023010)the Gusu Innovation and Entrepreneurship Leading Talent Program(ZXL2023188).
文摘Lead halide hybrids are promising switchable dielectric materials owing to their structural tunability,which enables thermotropic phase transitions.However,achieving large dielectric contrasts remains a significant challenge.Here,we demonstrate a strategy to markedly enhance the dielectric switching ratio(DSR)by engineering a phase-transition compound with elevated ionic conduction in the high-temperature phase via vacancy-enabled ionic transport.Using[C_(5)H_(12)N]_(2)PbCl_(4)(C_(5)H_(12)N^(+)=piperidinium)as a model,we synthesized a series of[C_(5)H_(12)N]_(2)-2xPb_(1-x)Mn_(x)Cl_(4)-2x(x=0.01-0.15)via solvent-free mechanochemistry.Mn^(2+)-doping introduces charge-compensating C_(5)H_(12)N^(+)and Cl-vacancies into the lattice,triggering a structural phase transition.As anticipated,the doped hybrids exhibit a substantially improved DSR,with the x=0.15 composition reaching an ultrahigh value of~10^(3),surpassing most reported dielectric switching materials.This enhancement is attributed to a grain boundary-induced barrier layer mechanism within the ion-conducting system.Our results establish vacancy-enabled ionic transport as a viable strategy for designing high-performance dielectric switching materials within soft halide frameworks.
