| 摘要 |
PURPOSE:To easily observe the symmetry of the pseudo Kikuchi beam pattern by illuminating a hollow, conical electron beam to a sample, with the illumination position of the incident electron beam located on a Laue zone ring. CONSTITUTION:The diffraction image of a sample 6 is formed on a fluorescent plate 8, and an arm 10 is moved in the X-direction so that the shadow of a stopper 9 is located on the primary Laue zone ring. The inclination angle theta of an incident electron beam to the sample 6 is gradually increased via a scan rotation circuit 4 so that the incident electron beam 1 is made to coincide with the shadow of the beam stopper 9 on the fluorescent plate 8. Next, the azimuth angle phi is rotated with the inclination angle theta fixed via the scan rotation circuit 4, and a hollow, conical electron beam is illuminated to the sample 6. Zero- order diffraction disk is overlapped around the crystal zone axis, thereby patterns in individual diffraction disks are also overlapped and averaged and made inconspicuous, on the other hand, pseudo Kikuchi beams are reinforced each other and clearly appear at the center of zero-order diffraction disks centering around the crystal zone axis. |
