| 摘要 |
PURPOSE:To obtain an accurate scanning electron diffraction pattern by providing a locking angle setting diaphragm between a scanning coil and sample level and making the device so that the diaphgram can be moved remotely from the outside of the microscope cylinder with a moving mechanism. CONSTITUTION:The deflection direction of an electron beam 1 focused with a focusing lens 12 is changed with a scanning coil 7, the electron beam 1 is changed in its direction toward the electron optical axis 2 with a magnetic field of an objective lens 3, and focused on the irradiation point 6 in the sample plate 5. A diaphgram plate 9 having a diaphgram 8a with an aperture D1 is inserted to the objective lens 3 to obtain a scanning electron diffraction pattern with a locking angle alpha2. A diaphgram 8b with an aperture D2 is also provided on the diaphgram plate 9, the diaphgram plate 9 is moved remotely from the outside of the microscope cylinder 11 with a moving mechanism 10 to coincide the diaphgram 8b on the electron optical axis 2 and a scanning electron diffraction pattern with a different locking angle is obtained. Thus a diffraction pattern with improved accuracy can be obtained. |
