本文研究开尔文探针力显微镜(KPFM)中多频率方法的实现。KPFM中的多频率方法同时激发微悬臂探针的第一次和第二次的本征机械振动模式并分别用于样品形貌和表面电势成像。据此,本文设计了一种基于传统比例-积分控制器基本原理的模拟式反...本文研究开尔文探针力显微镜(KPFM)中多频率方法的实现。KPFM中的多频率方法同时激发微悬臂探针的第一次和第二次的本征机械振动模式并分别用于样品形貌和表面电势成像。据此,本文设计了一种基于传统比例-积分控制器基本原理的模拟式反馈控制器,用以实现探针的调控。测试表明,该反馈控制器带宽可达约5 k Hz,并利用该反馈控制器研制出了多频率KPFM,其电势测量灵敏度优于5 m V。利用该多频率KPFM,对注入电荷后的介电薄膜样品进行测试,一次成像即可得到样品的形貌图及局域电势的二维分布图。该多频率KPFM技术可广泛应用于电子材料与器件的电特性表征。展开更多
The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)i...The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.展开更多
文摘本文研究开尔文探针力显微镜(KPFM)中多频率方法的实现。KPFM中的多频率方法同时激发微悬臂探针的第一次和第二次的本征机械振动模式并分别用于样品形貌和表面电势成像。据此,本文设计了一种基于传统比例-积分控制器基本原理的模拟式反馈控制器,用以实现探针的调控。测试表明,该反馈控制器带宽可达约5 k Hz,并利用该反馈控制器研制出了多频率KPFM,其电势测量灵敏度优于5 m V。利用该多频率KPFM,对注入电荷后的介电薄膜样品进行测试,一次成像即可得到样品的形貌图及局域电势的二维分布图。该多频率KPFM技术可广泛应用于电子材料与器件的电特性表征。
基金financial support from the National Natural Science Foundation of China(No.51961026)。
文摘The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.
基金Supported by the National Natural Science Foundation of China(11991063,62004207,61725505,62104118)the Shanghai Science and Technology Committee(2019SHZDZX01,19XD1404100,20YF1455900,20ZR1474000)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43010200)the Youth Innovation Promotion Association CAS(2018276)。
