Journal article
Study of Martensitic Phase Transformation in a NiTiCu Thin‐Film Shape‐Memory Alloy Using Photoelectron Emission Microscopy
Advanced functional materials, Vol.17(1), pp.161-167
01/2007
Handle:
https://hdl.handle.net/2376/108291
Abstract
Thermally induced martensitic phase transformation in a polycrystalline NiTiCu thin‐film shape‐memory alloy is probed using photoelectron emission microscopy (PEEM). In situ PEEM images reveal distinct changes in microstructure and photoemission intensity at the phase‐transition temperatures. In particular, images of the low‐temperature, martensite phase are brighter than that of the high‐temperature, austenite phase, because of the lower work function of the martensite. UV photoelectron spectroscopy shows that the effective work‐function changes by about 0.16 eV during thermal cycling. In situ PEEM images also show that the network of trenches observed on the room‐temperature film disappears suddenly during heating and reappears suddenly during subsequent cooling. These trenches are also characterized using atomic force microscopy at selected temperatures. The implications of these observations with respect to the spatial distribution of phases during thermal cycling in this thin‐film shape‐memory alloy are discussed.
Photoelectron emission microscopy is used to probe morphological and surface work‐function changes during the thermally induced martensitic phase transformation in a polycrystalline NiTiCu thin film. Low‐temperature martensite phase has a micrometer‐scale wrinklelike structure on the surface (see figure). When the sample is heated above the transition temperature, the image becomes dark and the wrinklelike structure disappears.
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Details
- Title
- Study of Martensitic Phase Transformation in a NiTiCu Thin‐Film Shape‐Memory Alloy Using Photoelectron Emission Microscopy
- Creators
- M CaiS. C LangfordM WuW HuangG XiongT. C DroubayA. G JolyK. M BeckW. P HessJ. T Dickinson
- Publication Details
- Advanced functional materials, Vol.17(1), pp.161-167
- Academic Unit
- Physics and Astronomy, Department of
- Publisher
- WILEY‐VCH Verlag; Weinheim
- Number of pages
- 7
- Grant note
- Department of Energy, Office of Science, Division of Chemical Sciences (DE‐FG03‐02ER45988)
- Identifiers
- 99900547425901842
- Language
- English
- Resource Type
- Journal article