Characterization of an amorphous carbon film covering a Mo grid during in situ heating TEM study

In the present study, we investigated the behavior of an amorphous carbon film covering a Mo grid at high temperature. It was found that metastable nanosized particles were formed on the carbon film at 400 °C. They finally became nanosized α-Mo2C crystals with an average size of 3.5 nm at 700 °C. Moreover, modification of the amorphous carbon support film was observed. High-resolution TEM images showed that the carbon film was transformed to irregular and disordered lamellar structures at 300 °C and to short-range ordered and crystallized structures at 700 °C. Based on these experimental results, we suggest selecting suitable metal grids and support films for the TEM specimen preparation and performing a chemical analysis of nanostructure materials in in situ heating experiment. Finally, it is expected that these results will be helpful for the appropriate experimental designs for the in situ TEM studies.