QUANTITATIVE HIGH-RESOLUTION ELECTRON-MICROSCOPY OF A HIGH-T-C SUPERCONDUCTOR TL2BA2CU1OY WITH THE IMAGING PLATE

A high-resolution electron microscope image of the high-T-c superconductor Tl2Ba2Cu1Oy was quantitatively observed by using the imaging plate. In order to quantitatively evaluate the difference between the intensity of the observed image and that of calculated images, a residual index R(HREM) (= Sigma\I-obs-I-cal\/Sigma I-obs) was calculated for 743 sampling points in the unit cell projected along the [010] direction. Although it has a rather complicated layered structure, R(HREM) = 0.0473 was obtained by choosing the experimental parameters and taking into account the partial occupancy of Tl atoms. Based on the analysis of the high-resolution electron microscope image of Tl2Ba2Cu1Oy, several requirements for further refinement of crystal structure analysis by quantitative high-resolution microscopy were discussed.