Experimental and theoretical evidence for the magic angle in transmission electron energy loss spectroscopy.
We present experimental measurements of the C K-ELNES of high temperature pyrolysed graphite and related crystalline materials as a function of collection angle and sample tilt. These results together with a corresponding theoretical analysis indicate that the so-called "magic angle" for EELS measurements of an anisotropic crystal such as graphite, where spectra are independent of sample orientation, is approximately two times the characteristic scattering angle. We briefly discuss the implications of this result for the experimental measurement of anisotropic structures, including interfaces, as well as for the detailed modelling of ELNES structures using advanced electronic structure calculations.
Daniels
Howard
H
Institute for Materials Research, University of Leeds, Leeds LS2 9JT, UK.
Brown
Andy
A
Scott
Andrew
A
Nichells
Tony
T
Rand
Brian
B
Brydson
Rik
R