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Development of the scanning time-resolved Kerr microscope
Nekula, Zdeněk ; Arregi Uribeetxebarria, Jon Ander (oponent) ; Wojewoda, Ondřej (vedoucí práce)
In recent days, magnetic materials, structures, and devices are getting more popular, especially those related to spintronics. Research and development of such magnetic samples require a way to observe magnetization with good spatial and temporal resolution. Most dynamic changes of magnetization are realized in nanoseconds or even faster. If we can detect these dynamic processes, we can reveal many exciting magnetization features and add the fourth dimension to our experiments. We introduce a scanning Kerr microscope working in two modes: static and dynamic. In static mode, our microscope detects a direction of magnetization in a variable magnetic field. In dynamic mode, we use a pump-probe method to reach a temporal resolution and observe a fast evolution of magnetization.
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Generation and applications of pulsed beam in an electron microscope
Nekula, Zdeněk ; Kozák,, Martin (oponent) ; Kolíbal, Miroslav (vedoucí práce)
Electron microscopes are used worldwide both in industry and basic research. This master thesis describes how to use small electrostatic deflectors to provide high time resolution in both transmission (TEM) and scanning (SEM) electron microscopes. The described method for TEM is a new solution utilizing a streak camera effect. This approach stands out for its simplicity, sub-picosecond time resolution, and flexible time range. Next, in SEM, a small electrostatic deflector makes a pulsed electron beam. This pulsed beam is used for time-resolved detection thanks to the stroboscopic effect. For SEM, the thesis demonstrates two new methods how to measure an electron pulse length, and also two applications of time-resolved detection. They are a time-resolved voltage contrast and a time-resolved electric field.
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Development of the scanning time-resolved Kerr microscope
Nekula, Zdeněk ; Arregi Uribeetxebarria, Jon Ander (oponent) ; Wojewoda, Ondřej (vedoucí práce)
In recent days, magnetic materials, structures, and devices are getting more popular, especially those related to spintronics. Research and development of such magnetic samples require a way to observe magnetization with good spatial and temporal resolution. Most dynamic changes of magnetization are realized in nanoseconds or even faster. If we can detect these dynamic processes, we can reveal many exciting magnetization features and add the fourth dimension to our experiments. We introduce a scanning Kerr microscope working in two modes: static and dynamic. In static mode, our microscope detects a direction of magnetization in a variable magnetic field. In dynamic mode, we use a pump-probe method to reach a temporal resolution and observe a fast evolution of magnetization.
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