Artículos de revistas
Atomic resolution imaging and spectroscopy of single Barium atoms and functional groups on graphene oxide
Fecha
2014-03-19Registro en:
Boothroyd, C. B.; Moreno, M. S.; Duchamp, M.; Kovács, A.; Monge, Natalia Eugenia; et al.; Atomic resolution imaging and spectroscopy of single Barium atoms and functional groups on graphene oxide; Elsevier Science; Ultramicroscopy; 145; 2014; 19-3-2014; 66-73
0304-3991
CONICET Digital
CONICET
Autor
Boothroyd, C. B.
Moreno, M. S.
Duchamp, M.
Kovács, A.
Monge, Natalia Eugenia
Morales, Gustavo Marcelo
Barbero, César Alfredo
Dunin Borkowski, R. E.
Resumen
We present an atomic resolution transmission electron microscopy (TEM) and scanning TEM (STEM) study of the local structure and composition of graphene oxide modified with Ba2+. In our experiments, which are carried out at 80 kV, the acquisition of contamination-free high-resolution STEM images is only possible while heating the sample above 400 °C using a highly stable heating holder. Ba atoms are identified spectroscopically in electron energy-loss spectrum images taken at 800 °C and are associated with bright contrast in high-angle annular dark-field STEM images. The spectrum images also show that Ca and O occur together and that Ba is not associated with a significant concentration of O. The electron dose used for spectrum imaging results in beam damage to the specimen, even at elevated temperature. It is also possible to identify Ba atoms in high-resolution TEM images acquired using shorter exposure times at room temperature, thereby allowing the structure of graphene oxide to be studied using complementary TEM and STEM techniques over a wide range of temperatures.