Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

Abstract
Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties. In this work, Pt deposited by FIB is characterized thermally, structurally, and chemically. Its thermal conductivity is found to be substantially lower than the bulk value of Pt, 7.2 W m-1 K-1 versus 71.6 W m-1 K-1 at room temperature. The low thermal conductivity is attributed to the nanostructure of the material and its chemical composition. Pt deposited by FIB is shown, via aberration corrected TEM, to be a segregated mix of nanocrystalline Pt and amorphous C with Ga and O impurities. Ga impurities mainly reside in the Pt while O is homogeneously distributed throughout. The Ga impurity, small grain size of the Pt, and the amorphous carbon between grains are the cause for the low thermal conductivity of this material. Since Pt deposited by FIB is a common material for affixing samples, this information can be used to assess systematic errors in thermal characterization of different nanosamples. This application is also demonstrated by thermal characterization of two carbon nanofibers and a correction using the reported thermal properties of the Pt deposited by FIB.

Citation
Alaie, S., Goettler, D. F., Jiang, Y.-B., Abbas, K., Baboly, M. G., Anjum, D. H., … Leseman, Z. C. (2015). Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam. Nanotechnology, 26(8), 085704. doi:10.1088/0957-4484/26/8/085704

Acknowledgements
This work was supported by the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering Experimental Program to Stimulate Competitive Research (EPSCoR) under Award DE-FG02-10ER46720. Portions of this work were carried out in the Manufacturing Training and Technology Center (MTTC), Center for MicroEngineered Materials' (CMEM) TEM Laboratory, and the Nanosynthesis Facility all at the University of New Mexico. SC thanks the King Abdullah University for Science and Technology (KAUST) for financial support.

Publisher
IOP Publishing

Journal
Nanotechnology

DOI
10.1088/0957-4484/26/8/085704

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