Hybrid ferroelastic crystals have garnered considerable interest due to their promising potential as mechanical switches and sensors.The anomalous ferroelastic phase transitions,in which ferroelasticity occurs in the ...Hybrid ferroelastic crystals have garnered considerable interest due to their promising potential as mechanical switches and sensors.The anomalous ferroelastic phase transitions,in which ferroelasticity occurs in the hightemperature phase rather than the low-temperature phase,are of particular interest,but they are sporadically-documented and none of them is involved in breaking of the chemical bonds.Herein,a hydroxyl-containing cation,i.e.,Me_(3)NOH^(+),is employed to construct a three-dimensional hybrid crystal(Me_(3)NOH)_(2)KBiCl_(6)(1).This crystal undergoes distinct twostep structural phase transitions with space-group changes of Pna21–P112_(1)–P63mc,belonging to an anomalous temperaturereversed mm2F2 ferroelastic transition and a normal 6mmF2 ferroelastic transition,respectively.The anomalous ferroelastic transition is entirely driven by switchable K–O coordination bonds involving breaking and reformation.Notably,the dynamic behavior of Me_(3)NOH^(+)cations along with the distortion of inorganic framework enables the manifestation of unusual“high-low-medium”second-harmonic generation-switching behaviors.This study presents the enormous benefits of switchable coordination bonds for inducing anomalous ferroelastic phase transitions,offering valuable insight for the exploration of new multifunctional ferroelastic materials.展开更多
近年来,病原体引起的流行病频发,对含能杀菌剂提出了迫切需求;它们可通过爆炸性反应快速地大面积抛洒以单质碘为主的高效广谱杀菌物质,但其高碘含量与高爆性能难以同时兼得.在此,我们报道了一类新型含能杀菌剂——多碘分子钙钛矿:(H_(2)...近年来,病原体引起的流行病频发,对含能杀菌剂提出了迫切需求;它们可通过爆炸性反应快速地大面积抛洒以单质碘为主的高效广谱杀菌物质,但其高碘含量与高爆性能难以同时兼得.在此,我们报道了一类新型含能杀菌剂——多碘分子钙钛矿:(H_(2)dabco)M(IO_(4))_(3)(dabco=1,4-二氮杂双环[2.2.2]辛烷,M=Na^(+)/K^(+)/Rb^(+)/NH_(4)^(+)分别对应DAI-1/2/3/4)和(H_(2)dabco)Na(H_(4)IO_(6))_(3)(DAI-X1).这些化合物具有立方钙钛矿结构,不仅具有高碘含量(49–54wt%),而且具有较高的爆速(6.331–6.558 km s^(-1))和爆压(30.69–30.88 GPa).特别地,DAI-4具有高达54.0 wt%的碘含量,以及6.558 km s^(-1)的爆速.激光扫描共聚焦显微镜观察和标准微量肉汤稀释法实验表明,DAI-4的爆炸产物对细菌(大肠杆菌、金黄色葡萄球菌和铜绿假单胞菌)具有广谱杀菌性.这类基于高碘酸根的分子钙钛矿具有易于放大合成、低成本、高爆轰性能和高碘含量的优点,是极具潜力的新型含能杀菌剂.展开更多
Ferroelasticity,as a mechanical counterpart of ferroelectricity and ferromagnetism,describes the nonlinear response of strain to stress with a hysteresis loop[1].Ferroelastic phase features with two or more switchable...Ferroelasticity,as a mechanical counterpart of ferroelectricity and ferromagnetism,describes the nonlinear response of strain to stress with a hysteresis loop[1].Ferroelastic phase features with two or more switchable orientation states of spontaneous strain[2,3],ensuring essential roles in shape memory,actuators,and mechanical switches[4].展开更多
基金supported by the National Natural Science Foundation Of China(22071273 and 21821003)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(23lgzy001).
文摘Hybrid ferroelastic crystals have garnered considerable interest due to their promising potential as mechanical switches and sensors.The anomalous ferroelastic phase transitions,in which ferroelasticity occurs in the hightemperature phase rather than the low-temperature phase,are of particular interest,but they are sporadically-documented and none of them is involved in breaking of the chemical bonds.Herein,a hydroxyl-containing cation,i.e.,Me_(3)NOH^(+),is employed to construct a three-dimensional hybrid crystal(Me_(3)NOH)_(2)KBiCl_(6)(1).This crystal undergoes distinct twostep structural phase transitions with space-group changes of Pna21–P112_(1)–P63mc,belonging to an anomalous temperaturereversed mm2F2 ferroelastic transition and a normal 6mmF2 ferroelastic transition,respectively.The anomalous ferroelastic transition is entirely driven by switchable K–O coordination bonds involving breaking and reformation.Notably,the dynamic behavior of Me_(3)NOH^(+)cations along with the distortion of inorganic framework enables the manifestation of unusual“high-low-medium”second-harmonic generation-switching behaviors.This study presents the enormous benefits of switchable coordination bonds for inducing anomalous ferroelastic phase transitions,offering valuable insight for the exploration of new multifunctional ferroelastic materials.
基金supported by the National Natural Science Foundation of China(22071273 and 21821003)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01C161)the Fundamental Innovation Team Fund(CXTD202001)。
文摘近年来,病原体引起的流行病频发,对含能杀菌剂提出了迫切需求;它们可通过爆炸性反应快速地大面积抛洒以单质碘为主的高效广谱杀菌物质,但其高碘含量与高爆性能难以同时兼得.在此,我们报道了一类新型含能杀菌剂——多碘分子钙钛矿:(H_(2)dabco)M(IO_(4))_(3)(dabco=1,4-二氮杂双环[2.2.2]辛烷,M=Na^(+)/K^(+)/Rb^(+)/NH_(4)^(+)分别对应DAI-1/2/3/4)和(H_(2)dabco)Na(H_(4)IO_(6))_(3)(DAI-X1).这些化合物具有立方钙钛矿结构,不仅具有高碘含量(49–54wt%),而且具有较高的爆速(6.331–6.558 km s^(-1))和爆压(30.69–30.88 GPa).特别地,DAI-4具有高达54.0 wt%的碘含量,以及6.558 km s^(-1)的爆速.激光扫描共聚焦显微镜观察和标准微量肉汤稀释法实验表明,DAI-4的爆炸产物对细菌(大肠杆菌、金黄色葡萄球菌和铜绿假单胞菌)具有广谱杀菌性.这类基于高碘酸根的分子钙钛矿具有易于放大合成、低成本、高爆轰性能和高碘含量的优点,是极具潜力的新型含能杀菌剂.
基金supported by the National Natural Science Foundation of China(22071273 and 21821003)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01C161).
文摘Ferroelasticity,as a mechanical counterpart of ferroelectricity and ferromagnetism,describes the nonlinear response of strain to stress with a hysteresis loop[1].Ferroelastic phase features with two or more switchable orientation states of spontaneous strain[2,3],ensuring essential roles in shape memory,actuators,and mechanical switches[4].
