Propagation of priors for more accurate and efficient spectroscopic functional fits and their application to ferroelectric hysteresis

Creange, N and Kelley, K P and Smith, C and Sando, D and Paull, O and Valanoor, N and Somnath, S and Jesse, S and Kalinin, S V and Vasudevan, R K (2021) Propagation of priors for more accurate and efficient spectroscopic functional fits and their application to ferroelectric hysteresis. Machine Learning: Science and Technology, 2 (4). 045002. ISSN 2632-2153

[thumbnail of Creange_2021_Mach._Learn.__Sci._Technol._2_045002.pdf] Text
Creange_2021_Mach._Learn.__Sci._Technol._2_045002.pdf - Published Version

Download (3MB)

Abstract

Multi-dimensional spectral-imaging is a mainstay of the scanning probe and electron microscopies, micro-Raman, and various forms of chemical imaging. In many cases, individual spectra can be fit to a specific functional form, with the model parameter maps, providing direct insight into material properties. Since spectra are often acquired across a spatial grid of points, spatially adjacent spectra are likely to be similar to one another; yet, this fact is almost never used when considering parameter estimation for functional fits. On datasets tried here, we show that by utilizing proximal information, whether it be in the spatial or spectral domains, it is possible to improve the reliability and increase the speed of such functional fits by ∼2–3×, as compared to random priors. We explore and compare three distinct new methods: (a) spatially averaging neighborhood spectra, and propagating priors based on functional fits to the averaged case, (b) hierarchical clustering-based methods where spectra are grouped hierarchically based on response, with the priors propagated progressively down the hierarchy, and (c) regular clustering without hierarchical methods with priors propagated from fits to cluster means. Our results highlight that utilizing spatial and spectral neighborhood information is often critical for accurate parameter estimation in noisy environments, which we show for ferroelectric hysteresis loops acquired on a prototypical PbTiO3 thin film with piezoresponse spectroscopy. This method is general and applicable to any spatially measured spectra where functional forms are available. Examples include exploring the superconducting gap with tunneling spectroscopy, using the Dynes formula, or current–voltage curve fits in conductive atomic force microscopy mapping. Here we explore the problem for ferroelectric hysteresis, which, given its large parameter space, constitutes a more difficult task than, for example, fitting current–voltage curves with a Schottky emission formula (Chiu 2014 Adv. Mater. Sci. Eng. 2014 578168).

Item Type: Article
Subjects: Science Repository > Multidisciplinary
Depositing User: Managing Editor
Date Deposited: 04 Jul 2023 03:56
Last Modified: 09 Oct 2023 05:49
URI: http://research.manuscritpub.com/id/eprint/2578

Actions (login required)

View Item
View Item