Structure Analysis using Time-of-Flight Momentum Microscopy with Hard X-rays: Status and Prospects

TL;DR

This paper reports on the development and application of Time-of-Flight Momentum Microscopy with hard X-rays for detailed bulk structural analysis, demonstrating its effectiveness through experiments on various materials.

Contribution

It introduces a novel full-field imaging technique for hXPD capable of high kinetic energies and large k-space coverage, advancing bulk structural analysis methods.

Findings

Successful application to NbSe2, SrTiO3, and GaAs films.

Good agreement between Bloch-wave calculations and experimental data.

Effective dopant-site analysis in semiconductors.

Abstract

X-ray photoelectron diffraction (XPD) has developed into a powerful technique for the structural analysis of solids. Extension of the technique into the hard-X-ray range (hXPD) gives access to true bulk information. Here we give a status report on hXPD experiments using a novel full-field imaging technique: Time-of-flight momentum microscopy (ToF-MM). A special variant of ToF-MM is capable of recording high kinetic energies (up to >7keV) and enlarged k-fields-of-view. We present applications that are specific for high kinetic energies. The strong site specificity of hXPD is exemplified for NbSe2, the cubic-to-tetragonal transition in SrTiO3 and the zinc-blende structure in epitaxial GaAs films. Bloch-wave calculations show a very good agreement with experiment and reveal fingerprint-like signatures of emitter sites in host lattices. We show a dopant-site analysis in two semiconductors (Mn in GaAs and Te in Si). Hard-X-ray ARPES plus core-level hXPD enable eliminating the strong diffraction signature imprinted in HARPES maps.