title: Experimental and theoretical evidence for the magic angle in transmission electron energy loss spectroscopy.
abstract: 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.
authors.affiliation: Institute for Materials Research, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Howard
authors.initials: H
authors.lastname: Daniels
authors.forename: Andy
authors.initials: A
authors.lastname: Brown
authors.forename: Andrew
authors.initials: A
authors.lastname: Scott
authors.forename: Tony
authors.initials: T
authors.lastname: Nichells
authors.forename: Brian
authors.initials: B
authors.lastname: Rand
authors.forename: Rik
authors.initials: R
authors.lastname: Brydson