The structure and local chemical properties of boron-terminated   tetravacancies in hexagonal boron-nitride
  Imaging and spectroscopy performed in a low-voltage scanning transmission electron microscope (LV-STEM) are used to characterize the structure and chemical properties of boron-terminated tetravacancies in hexagonal boron nitride (h-BN). We confirm earlier theoretical predictions about the structure of these defects and identify new features in the electron energy-loss spectra (EELS) of B atoms using high resolution chemical maps, highlighting differences between these areas and pristine sample regions. We correlate our experimental data with calculations which help explain our observations. 
Ovidiu Cretu, Yung-Chang Lin, Masanori Koshino, Luiz H. G. Tizei,   Zheng Liu, Kazutomo Suenaga
cond-mat.mtrl-sci