Large pyroelectric and energy harvesting properties have been attracting increasing attentions due to the practical applications in infrared detectors and energy harvesting technologies.Ferroelectricantiferroelectric(...Large pyroelectric and energy harvesting properties have been attracting increasing attentions due to the practical applications in infrared detectors and energy harvesting technologies.Ferroelectricantiferroelectric(FE-AFE)phase transitions are usually accompanied by a sharp drop in polarization,which will lead to excellent pyroelectric properties and energy harvesting density.Therefore,FE-AFE phase boundary design is an effective strategy to develop new pyroelectric materials.In this paper,Pb(Lu_(1/2)Nb_(1/2))O_(3)-PbTiO_(3) (PLN-PT)single crystals with FE-AFE phase transitions were obtained by molten salt growth method.The temperature-induced FE-AFE phase transition was verified by temperaturedependent macrodomain structure,DSC curves and dielectric properties.Obviously,PLN-PT crystals display excellent peak pyroelectric coefficient(~6.8μC/(cm^(2)·K)with a maximum depolarization temperature of 118℃.Meanwhile,the pyroelectric energy harvesting density is as high as 2.62 J/cm3,which is much higher than other pyroelectric materials.The results reveal that the PLN-PT crystal is a promising candidate for infrared detectors and energy harvesting devices.展开更多
Electro-optical materials are crucial for lasers and modulators applications.Perovskite ferroelectric crystals,characterized by oxygen octahedrons and superior dipole migration capabilities,are recognized for their hi...Electro-optical materials are crucial for lasers and modulators applications.Perovskite ferroelectric crystals,characterized by oxygen octahedrons and superior dipole migration capabilities,are recognized for their high electro-optic coefficients.However,the application of perovskite ferroelectric crystals is often limited by reduced optical transparency,which results from light scattering and reflection at domain walls.In this study,we implemented a structure dimensionality reduction strategy to successfully transform a three-dimensional structure KNbO_(3)(KNO)crystal into a quasi-two-dimensional layered structure K_(3)Nb_(3)B_(2)O_(12)(KNBO)crystal through BO_(3)planar groups.This modification restricts the mobility of B-site ions within the layers while preserving significant spontaneous polarization along the interlayer direction,thus converting multipolar axis into a unipolar axis in the ferroelectric.This alteration in the direction of spontaneous polarization modifies the domain structure,thereby minimizing the scattering effects of the domain walls.As a result,the KNBO crystal exhibits a large effective electro-optic(EO)coefficient of 50.14 pm/V and a high transmittance exceeding 80%in the 330-2500 nm wavelength range.These properties surpass those of currently available commercial EO crystals.This research establishes a model for enhancing transparency and EO coefficient through structural design,offering potential applications to other EO crystals.展开更多
基金Project supported by the National Natural Science Foundation of China(51902307,11904362,11974349)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)+1 种基金Youth Innovation Promotion Association CASScience and Technology Project of Fujian Province(2020H0038,2019H0052)。
文摘Large pyroelectric and energy harvesting properties have been attracting increasing attentions due to the practical applications in infrared detectors and energy harvesting technologies.Ferroelectricantiferroelectric(FE-AFE)phase transitions are usually accompanied by a sharp drop in polarization,which will lead to excellent pyroelectric properties and energy harvesting density.Therefore,FE-AFE phase boundary design is an effective strategy to develop new pyroelectric materials.In this paper,Pb(Lu_(1/2)Nb_(1/2))O_(3)-PbTiO_(3) (PLN-PT)single crystals with FE-AFE phase transitions were obtained by molten salt growth method.The temperature-induced FE-AFE phase transition was verified by temperaturedependent macrodomain structure,DSC curves and dielectric properties.Obviously,PLN-PT crystals display excellent peak pyroelectric coefficient(~6.8μC/(cm^(2)·K)with a maximum depolarization temperature of 118℃.Meanwhile,the pyroelectric energy harvesting density is as high as 2.62 J/cm3,which is much higher than other pyroelectric materials.The results reveal that the PLN-PT crystal is a promising candidate for infrared detectors and energy harvesting devices.
基金supported by the National Natural Science Foundation of China(52172009,52102011,12275274,52202011)the Science and Technology Project of Fujian Province(2021H0043)+3 种基金the Youth Cultivation Program of Chinese Academy of Sciences(JCPYJJ-22032)the Natural Science Foundation of Fujian Province(2023J01158)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2023317)the China Association for Science and Technology Young Elite Scientist Sponsorship Program by Cast(YESS20210304).
文摘Electro-optical materials are crucial for lasers and modulators applications.Perovskite ferroelectric crystals,characterized by oxygen octahedrons and superior dipole migration capabilities,are recognized for their high electro-optic coefficients.However,the application of perovskite ferroelectric crystals is often limited by reduced optical transparency,which results from light scattering and reflection at domain walls.In this study,we implemented a structure dimensionality reduction strategy to successfully transform a three-dimensional structure KNbO_(3)(KNO)crystal into a quasi-two-dimensional layered structure K_(3)Nb_(3)B_(2)O_(12)(KNBO)crystal through BO_(3)planar groups.This modification restricts the mobility of B-site ions within the layers while preserving significant spontaneous polarization along the interlayer direction,thus converting multipolar axis into a unipolar axis in the ferroelectric.This alteration in the direction of spontaneous polarization modifies the domain structure,thereby minimizing the scattering effects of the domain walls.As a result,the KNBO crystal exhibits a large effective electro-optic(EO)coefficient of 50.14 pm/V and a high transmittance exceeding 80%in the 330-2500 nm wavelength range.These properties surpass those of currently available commercial EO crystals.This research establishes a model for enhancing transparency and EO coefficient through structural design,offering potential applications to other EO crystals.
