Title: Accurate, rapid identification of dislocation lines in coherent diffractive imaging via a min-max optimization formulation

Abstract

Defects such as dislocations impact materials properties and their response during external stimuli. Imaging these defects in their native operating conditions to establish the structure-function relationship and, ultimately, to improve performance via defect engineering has remained a considerable challenge for both electron-based and x-ray-based imaging techniques. While Bragg coherent x-ray diffractive imaging (BCDI) is successful in many cases, nuances in identifying the dislocations has left manual identification as the preferred method. Derivative-based methods are also used, but they can be inaccurate and are computationally inefficient. Here we demonstrate a derivative-free method that is both more accurate and more computationally efficient than either derivative-or human-based methods for identifying 3D dislocation lines in nanocrystal images produced by BCDI. We formulate the problem as a min-max optimization problem and show exceptional accuracy for experimental images. We demonstrate a 227x speedup for a typical experimental dataset with higher accuracy over current methods. We discuss the possibility of using this algorithm as part of a sparsity-based phase retrieval process. Here, we also provide MATLAB code for use by other researchers.

Authors:

Ulvestad, A.  ^[1];

• Search DOE PAGES for author "Ulvestad, A."
• Search DOE PAGES for ORCID "0000-0003-4611-2561"

Menickelly, M. ^[1]; Wild, S. M. ^[1]

---

+ Show Author Affiliations

1. Argonne National Lab. (ANL), Lemont, IL (United States)

Publication Date:

Wed Jan 10 00:00:00 EST 2018

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1425269

Alternate Identifier(s):

OSTI ID: 1416468

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

AIP Advances

Additional Journal Information:

Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2158-3226

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

47 OTHER INSTRUMENTATION