Nanocrystallization of amorphous M-Si thin film composites (M=Cr, Mn) and their thermoelectric properties

Journal Article · Tue Jun 26 04:00:00 EDT 2012 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4731536· OSTI ID:22068983

Burkov, A T; Novikov, S V; Schumann, J ^[1]

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1. A.F. Ioffe Physical-Technical Institute, Sankt-Petersburg, 194021 (Russian Federation)

We report on electrical resistivity and thermoelectric power of Cr-Si and Mn-Si composite films at temperatures from 300 K to 1000 K. The films were deposited on unheated Si/SiO{sub 2} substrates by magnetron sputtering from composite targets. The as-deposited films have amorphous structure. We use annealing with in-situ transport properties measurements to transform the films into nanocrystalline state with continuous monitoring their state. Nanocrystallization is considered as a promising way to improve thermoelectric efficiency, primarily due to reduction of lattice thermal conductivity {kappa}. Among variety of methods for fabrication of NC materials, crystallization from amorphous state has features which are crucially important with respect to their electronic transport properties: since the crystallites and their interfaces are formed in this method via solid state reaction, the NC samples are dense and the interfaces are clean. This removes additional factors affecting properties of a nanocrystalline composite, such as contamination of nanocrystal interfaces by elements from environment or nanocrystal lattice distortion during nanocrystallization. Depending on the initial film composition, the films are transformed during annealing into single phase or multi-phase nanocrystalline composites with average grain size of 10 nm to 20 nm. We study the crystallization kinetics, stability of amorphous and nanocrystalline state and relation between electronic transport properties and structural state of the composites.

• OSTI ID: 22068983
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1449; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
AMORPHOUS STATE
ANNEALING
CHROMIUM SILICIDES
COMPOSITE MATERIALS
CRYSTALLIZATION
CRYSTALS
DEPOSITION
ELECTRIC CONDUCTIVITY
FABRICATION
GRAIN SIZE
INTERFACES
MANGANESE SILICIDES
NANOSTRUCTURES
SEMICONDUCTOR MATERIALS
SILICON
SUBSTRATES
THERMAL CONDUCTIVITY
THERMOELECTRIC PROPERTIES
THIN FILMS