Ferroelectric hysteresis loop measurement under high driving frequency generally faces great challenges.Parasitic factors in testing circuits such as leakage current and RC delay could result in abnormal hysteresis lo...Ferroelectric hysteresis loop measurement under high driving frequency generally faces great challenges.Parasitic factors in testing circuits such as leakage current and RC delay could result in abnormal hysteresis loops with erroneous rem-nant polarization(P_(r))and coercive field(E_(c)).In this study,positive-up-negative-down(PUND)measurement under a wide fre-quency range was performed on a 10-nm thick Hf_(0.5)Zr_(0.5)O_(2) ferroelectric film.Detailed analysis on the leakage current and RC delay was conducted as the polarization switching occurs in the FE capacitor.After considering the time lag caused by RC delay,reasonable calibration of current response over the voltage pulse stimulus was employed in the integral of polarization current over time.In such a method,rational P-V loops measured at high frequencies(>1 MHz)was successfully achieved.This work provides a comprehensive understanding on the effect of parasitic factors on the polarization switching behavior of FE films.展开更多
In this work,we have presented a spin-coating method to produce thin films started with pure BiCrO3（BCO）and ended up with BiFeO3（BFO）by increasing x values in the（BiFeO3）x-（BiCrO3）1-x composites.All the produc...In this work,we have presented a spin-coating method to produce thin films started with pure BiCrO3（BCO）and ended up with BiFeO3（BFO）by increasing x values in the（BiFeO3）x-（BiCrO3）1-x composites.All the produced thin films have been crystallized at the annealing temperatures of 400 ℃ for 0.5 h.The XRD and EDAX spectrums give insight that the two crystal phases related to BCO and BFO stayed together within the thin film matrices.SEM analysis showed that the prepared composite had macroporous morphology with interconnected pores and its width（size）decreased with increasing x values.The strong correlations are observed among the microstructure,dielectric,ferroelectric,ferromagnetic properties and Fe concentration.Among all composites,the composition of 0.75 shows an attractive magnetization,polarization,switching and improved dielectric behaviors at room temperature.Significant increase in the multiferroic characteristics of 0.75 composition is due to arise of lower leakage current by causing reduction in oxygen vacancy density,and enhancement of super-exchange magnetic interaction between Fe3＋ and Cr3＋ at BFO/BCO interface layers.Our result shows that the thin layer on Pt（111）/Ti/SiO2/Si substrate possesses simultaneously improved ferroelectric and ferromagnetic properties which make an inaccessible potential application for nonvolatile ferroelectric memories.展开更多
基金supported by the Ministry of Science and Technology(MOST)of China under Grant 2016YFA0203800in part by the National Natural Science Foundation of China under Grants 61834009,62025406,92064003,61821091the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant XDB44010300。
文摘Ferroelectric hysteresis loop measurement under high driving frequency generally faces great challenges.Parasitic factors in testing circuits such as leakage current and RC delay could result in abnormal hysteresis loops with erroneous rem-nant polarization(P_(r))and coercive field(E_(c)).In this study,positive-up-negative-down(PUND)measurement under a wide fre-quency range was performed on a 10-nm thick Hf_(0.5)Zr_(0.5)O_(2) ferroelectric film.Detailed analysis on the leakage current and RC delay was conducted as the polarization switching occurs in the FE capacitor.After considering the time lag caused by RC delay,reasonable calibration of current response over the voltage pulse stimulus was employed in the integral of polarization current over time.In such a method,rational P-V loops measured at high frequencies(>1 MHz)was successfully achieved.This work provides a comprehensive understanding on the effect of parasitic factors on the polarization switching behavior of FE films.
基金supported by Department of Science and Technology (SB/S2/CMP- 028/2013), New Delhi, India
文摘In this work,we have presented a spin-coating method to produce thin films started with pure BiCrO3（BCO）and ended up with BiFeO3（BFO）by increasing x values in the（BiFeO3）x-（BiCrO3）1-x composites.All the produced thin films have been crystallized at the annealing temperatures of 400 ℃ for 0.5 h.The XRD and EDAX spectrums give insight that the two crystal phases related to BCO and BFO stayed together within the thin film matrices.SEM analysis showed that the prepared composite had macroporous morphology with interconnected pores and its width（size）decreased with increasing x values.The strong correlations are observed among the microstructure,dielectric,ferroelectric,ferromagnetic properties and Fe concentration.Among all composites,the composition of 0.75 shows an attractive magnetization,polarization,switching and improved dielectric behaviors at room temperature.Significant increase in the multiferroic characteristics of 0.75 composition is due to arise of lower leakage current by causing reduction in oxygen vacancy density,and enhancement of super-exchange magnetic interaction between Fe3＋ and Cr3＋ at BFO/BCO interface layers.Our result shows that the thin layer on Pt（111）/Ti/SiO2/Si substrate possesses simultaneously improved ferroelectric and ferromagnetic properties which make an inaccessible potential application for nonvolatile ferroelectric memories.
