In situ measurements of the axial expansion of palladium microdisks during hydrogen exposure using diffraction phase microscopy

Chris Edwards, Steven J. McKeown, Jerry Zhou, Gabriel Popescu, Lynford L. Goddard

Research output: Contribution to journalArticle

Abstract

We measured the height of Pd microdisks during H2 exposure using epi-illumination diffraction phase microscopy, a quantitative phase imaging technique for capturing nanoscale dynamics in situ. From these microdisk height measurements, we extracted the axial expansion coefficient as a function of H2 concentration as well as image sequences that show the instantaneous rate of axial expansion in a spatially and temporally resolved manner. Quantifying these two parameters is important in modeling Pd-based H2 sensors. For H2 concentrations below 0.5%, i.e. an order of magnitude below the lower explosive limit, the axial expansion coefficient followed the Freundlich distribution: Δh(c) = 1.28 c0.51 where Δh is the percentage change in height of the Pd microdisk and c is the percent concentration of H2 in N2. The fit agrees well with the anticipated square root dependence for diatomic gas.

Original languageEnglish (US)
Pages (from-to)2559-2564
Number of pages6
JournalOptical Materials Express
Volume4
Issue number12
DOIs
StatePublished - Jan 1 2014

Fingerprint

Palladium
Hydrogen
Microscopic examination
Diffraction
Lighting
Gases
Imaging techniques
Sensors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

In situ measurements of the axial expansion of palladium microdisks during hydrogen exposure using diffraction phase microscopy. / Edwards, Chris; McKeown, Steven J.; Zhou, Jerry; Popescu, Gabriel; Goddard, Lynford L.

In: Optical Materials Express, Vol. 4, No. 12, 01.01.2014, p. 2559-2564.

Research output: Contribution to journalArticle

@article{1c71b80cef7445879e1a7dfcee4d6053,
title = "In situ measurements of the axial expansion of palladium microdisks during hydrogen exposure using diffraction phase microscopy",
abstract = "We measured the height of Pd microdisks during H2 exposure using epi-illumination diffraction phase microscopy, a quantitative phase imaging technique for capturing nanoscale dynamics in situ. From these microdisk height measurements, we extracted the axial expansion coefficient as a function of H2 concentration as well as image sequences that show the instantaneous rate of axial expansion in a spatially and temporally resolved manner. Quantifying these two parameters is important in modeling Pd-based H2 sensors. For H2 concentrations below 0.5{\%}, i.e. an order of magnitude below the lower explosive limit, the axial expansion coefficient followed the Freundlich distribution: Δh(c) = 1.28 c0.51 where Δh is the percentage change in height of the Pd microdisk and c is the percent concentration of H2 in N2. The fit agrees well with the anticipated square root dependence for diatomic gas.",
author = "Chris Edwards and McKeown, {Steven J.} and Jerry Zhou and Gabriel Popescu and Goddard, {Lynford L.}",
year = "2014",
month = "1",
day = "1",
doi = "10.1364/OME.4.002559",
language = "English (US)",
volume = "4",
pages = "2559--2564",
journal = "Optical Materials Express",
issn = "2159-3930",
publisher = "The Optical Society",
number = "12",

}

TY - JOUR

T1 - In situ measurements of the axial expansion of palladium microdisks during hydrogen exposure using diffraction phase microscopy

AU - Edwards, Chris

AU - McKeown, Steven J.

AU - Zhou, Jerry

AU - Popescu, Gabriel

AU - Goddard, Lynford L.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - We measured the height of Pd microdisks during H2 exposure using epi-illumination diffraction phase microscopy, a quantitative phase imaging technique for capturing nanoscale dynamics in situ. From these microdisk height measurements, we extracted the axial expansion coefficient as a function of H2 concentration as well as image sequences that show the instantaneous rate of axial expansion in a spatially and temporally resolved manner. Quantifying these two parameters is important in modeling Pd-based H2 sensors. For H2 concentrations below 0.5%, i.e. an order of magnitude below the lower explosive limit, the axial expansion coefficient followed the Freundlich distribution: Δh(c) = 1.28 c0.51 where Δh is the percentage change in height of the Pd microdisk and c is the percent concentration of H2 in N2. The fit agrees well with the anticipated square root dependence for diatomic gas.

AB - We measured the height of Pd microdisks during H2 exposure using epi-illumination diffraction phase microscopy, a quantitative phase imaging technique for capturing nanoscale dynamics in situ. From these microdisk height measurements, we extracted the axial expansion coefficient as a function of H2 concentration as well as image sequences that show the instantaneous rate of axial expansion in a spatially and temporally resolved manner. Quantifying these two parameters is important in modeling Pd-based H2 sensors. For H2 concentrations below 0.5%, i.e. an order of magnitude below the lower explosive limit, the axial expansion coefficient followed the Freundlich distribution: Δh(c) = 1.28 c0.51 where Δh is the percentage change in height of the Pd microdisk and c is the percent concentration of H2 in N2. The fit agrees well with the anticipated square root dependence for diatomic gas.

UR - http://www.scopus.com/inward/record.url?scp=84920109334&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84920109334&partnerID=8YFLogxK

U2 - 10.1364/OME.4.002559

DO - 10.1364/OME.4.002559

M3 - Article

AN - SCOPUS:84920109334

VL - 4

SP - 2559

EP - 2564

JO - Optical Materials Express

JF - Optical Materials Express

SN - 2159-3930

IS - 12

ER -