Determination of Burgers vectors of dislocations in monoclinic $\beta$-Ga$_2$O$_3$ crystals by large-angle convergent-beam electron diffraction

TL;DR

This paper demonstrates that large-angle convergent-beam electron diffraction (LACBED) can effectively determine Burgers vectors of dislocations in monoclinic $eta$-Ga$_2$O$_3$ crystals, providing a reliable alternative to traditional methods.

Contribution

The study introduces a new application of LACBED for Burgers vector determination in non-orthogonal systems like $eta$-Ga$_2$O$_3$, using a metric tensor-free evaluation method.

Findings

Burgers vectors of nanoindentation-induced dislocations were unambiguously identified using LACBED.

The LACBED results were consistent with weak-beam dark-field imaging.

The framework allows evaluation of $g \, \cdot \, b$ without a metric tensor in non-orthogonal lattices.

Abstract

We demonstrate the applicability of large-angle convergent-beam electron diffraction (LACBED) for Burgers vector determination in monoclinic $\beta$-Ga$_2$O$_3$. The inner product $g \cdot b$ in this non-orthogonal system can be evaluated without a metric tensor by using the dual relationship between real and reciprocal lattice bases. Based on this framework, Burgers vectors of dislocations introduced by nanoindentation were unambiguously determined from LACBED node counts. The results are consistent with weak-beam dark-field imaging, confirming the effectiveness of LACBED for $\beta$-Ga$_2$O$_3$.