SINTERING AND OXIDATION USING A NOVEL ULTRAHIGH-VACUUM TRANSMISSION ELECTRON-MICROSCOPE WITH IN-SITU MAGNETRON SPUTTERING

The synthesis and processing of materials is often highly sensitive to the presence of trace contaminants and a number of technologically im portant materials demand the clean conditions associated with an ultra high vacuum environment. With increasing interest in understanding mat erials phenomena occurring on smaller and smaller length scales, the t ransmission electron microscope is finding increasing application in t he characterization of new materials and processes. The need for ex si tu sample preparation prior to analysis can raise questions regarding the validity of the data, however, due to contamination and the introd uction of microstructural artifacts. In this paper we discuss the appl ication of the ultrahigh vacuum transmission electron microscope to in situ studies of materials synthesis. To illustrate the capabilities o f the electron microscope in this context, we present two case studies : the synthesis and subsequent sintering of supported copper nanoparti cles, and the initial stages of the growth of Cu2O on clean (001) Cu. We describe the novel aspects of the instrumentation used, the methods of sample preparation, and our application of the plan-view imaging t echnique to in situ investigations. Microsc. Res. Tech. 42:302-308, 19 98. (C) 1998 Wiley-Liss, Inc.