PROBLEMS ASSOCIATED WITH IMAGING RESISTIVE BARRIERS IN BATIO3 PTC CERAMICS USING THE SEM CONDUCTIVE MODE

The micro-electrical properties of BaTiO3 have been studied using the remote electron beam induced current technique. Difficulties associate d with applying this technique to low resistance, inhomogeneous cerami cs are discussed and illustr ated with the example of PTCR materials. At temperatures above the Curie temperature, contrast steps correspond ing to resistive interfaces are observed with differing sensitivities according to the imaging conditions used. The image noise decreases an d the current sensitivity increases with the sample resistance. Remote electron beam induced current contrast in BaTiO3, showing the high re sistivity transition does not occur uniformly as a function of tempera ture across all grain boundaries.