Fig. 2: Crystallographic quality and phonon spectra of monolayer h-BN/Cu foil.
From: Observation of the nonanalytic behavior of optical phonons in monolayer hexagonal boron nitride
a Atomic-resolution STM image (scanned at 0.9 V and 0.3 nA). b LEED pattern, obtained at room temperature with an incident beam energy of 140 eV. c 2D energy-momentum mappings of 2D-HREELS along the Γ-M and Γ-K directions. d The second derivative results correspond to b. The purple dashed lines mark the replica signals of the phonon. e–g EDCs corresponding to the #1 (specular direction), #2 (momentum 0.2 Å−1), and #3 (momentum 0.5 Å−1) dashed dot lines in b, respectively. The green curves in c and d are calculated phonon dispersions by considering the 2D implementation of the nonanalytical-term correction27,28.
