Colloidal Phase-Change Materials: Synthesis of Monodisperse GeTe Nanoparticles and Quantification of Their Size-Dependent Crystallization

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Date
2018Type
- Journal Article
Citations
Cited 12 times in
Web of Science
Cited 13 times in
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ETH Bibliography
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Abstract
Phase-change memory materials refer to a class of materials that can exist in amorphous and crystalline phases with distinctly different electrical or optical properties, as well as exhibit outstanding crystallization kinetics and optimal phase transition temperatures. This paper focuses on the potential of colloids as phase-change memory materials. We report a novel synthesis for amorphous GeTe nanoparticles based on an amide-promoted approach that enables accurate size control of GeTe nanoparticles between 4 and 9 nm, narrow size distributions down to 9–10%, and synthesis upscaling to reach multigram chemical yields per batch. We then quantify the crystallization phase transition for GeTe nanoparticles, employing high-temperature X-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. We show that GeTe nanoparticles crystallize at higher temperatures than the bulk GeTe material and that crystallization temperature increases with decreasing size. We can explain this size-dependence using the entropy of crystallization model and classical nucleation theory. The size-dependences quantified here highlight possible benefits of nanoparticles for phase-change memory applications. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000288007Publication status
publishedExternal links
Journal / series
Chemistry of MaterialsVolume
Pages / Article No.
Publisher
American Chemical SocietyOrganisational unit
03895 - Wood, Vanessa / Wood, Vanessa
Funding
161249 - Colloidal nanocrystals of intermetallic compounds and alloys for phase-change memory applications (SNF)
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Citations
Cited 12 times in
Web of Science
Cited 13 times in
Scopus
ETH Bibliography
yes
Altmetrics