Dr. Haruta, M. and Assoc Prof Kurata, H., ”Direct Observation of Crystal Defects in Organic Molecular Crystals of Copper Hexachlorophthalocyanine by STEM-EELS” (Published in “Scientific Reports,” 7 February 2012)

Direct Observation of Crystal Defects in Organic Molecular Crystals of Copper Hexachlorophthalocyanine by STEM-EELS

 

Published in Scientific Reports “(Online Publication, February 7, 2012).

Assoc Prof. Kurata, H. and Dr. Haruta, M. (from left)
Dr. Haruta, M. (presently, in in NIMS) and Assoc Prof Kurata, H. (Electron Microscopy and Crystal Chemistry, Advanced Research Center for Beam Science )

Atomic resolution images of copper hexachlorophthalocyanine (C16CuPc) thin films have been observed by the annular bright field (ABF) and annular dark field (ADF) imaging using an aberration-corrected scanning transmission electron microscope equipped with a nano-tip field emission gun. By using the low-dose technique and an optimized detection angle, we were able to visualize the contrast of light element (C and N) together with the heavier elements (Cl and Cu) within the molecular column. We were also able to identify unexpected molecular orientation in the grain boundaries along the {110} crystallographic planes giving rise to stacking faults.

 
Figure 1: (a) Annular bright field image of C16CuPc crystal. (b) Annular dark field image of C16CuPc crystal. (c) Annular dark field image of complex defect region. The stacking fault was observed along the (110) plane and C16CuPc molecules with irregular orientation were identified in the grain boundary (GB) as a line contrast.
Haruta, M.; Kurata, H., Direct Observation of Crystal Defects in Organic Molecular Crystals of Copper Hexachlorophthalocyanine by STEM-EELS, Scientific Reports, 2, 252; DOI:10.1038/srep00252 (2012).