ELECTRON SPECTROSCOPIC IMAGING OF (BI,PB)(2)SR2CAN-1CUNO4-T-C SUPERCONDUCTING PHASES IN THE TEM(2N+DELTA HIGH)

This paper deals with the imaging of the (Bi,Pb)(2)Sr2CaCu2O8+delta an d the (Bi,Pb)(2)Sr2Ca2Cu3O10+delta high-T-c superconducting phases by electron spectroscopic imaging in the TEM. Intergrowth of (Bi,Pb)(2)Sr 2CaCu2O8+delta and (Bi,Pb)(2)Sr2Ca2Cu3O10+delta on the nm scale occurs on (0 0 1) planes and requires imaging conditions with the electron b eam being parallel to the (0 0 1) planes. Experimental settings for th e acquisition of Ca-L jump ratio images are described which yield opti mum contrast between the two phases and results obtained under these c onditions are shown. For the acquisition of ESI images a systematic ro w of (0 0 1) reflections is excited and diffraction effects with varyi ng specimen thickness are significant. A Bloch wave calculation for es timating these diffraction effects quantitatively was carried out and yielded a substantial decrease of electron intensities in the objectiv e aperture with increasing specimen thickness.