Evolution of Thermoelectric β-FeSi2 Phase by Cryo Milling and Sintering

Development of high temperature thermoelectric materials, like β-FeSi 2 , is the need of twenty-first century to convert waste heat energy to electrical energy. The increasing interest in bulk semiconducting iron disilicide, β-FeSi 2 , is due to the advantages of its high thermoelectric power, high...

Full description

Saved in:
Bibliographic Details
Published inTransactions of the Indian Institute of Metals Vol. 70; no. 1; pp. 167 - 174
Main Authors Poddar, V. S., Dhokey, N. B., Butee, S. P., Revade, N. B., Thombre, M. M., Purohit, R. D., Prakash, Deep
Format Journal Article
LanguageEnglish
Published New Delhi Springer India 2017
Springer Nature B.V
Subjects
Absorptivity
Chemistry and Materials Science
Corrosion and Coatings
Disilicides
Heat treatment
High temperature
Infrared detectors
Intermetallic compounds
Iron silicide
Materials Science
Mechanical alloying
Metallic Materials
Optical communication
Optical fibers
Process parameters
Semiconductor materials
Sintered compacts
Sintering
Sintering (powder metallurgy)
Technical Paper
Thermoelectric materials
Tribology
Thermoelectric
β-FeSi
Cryo milling
Sintering
Online AccessGet full text

Cover

More Information
Summary:Development of high temperature thermoelectric materials, like β-FeSi 2 , is the need of twenty-first century to convert waste heat energy to electrical energy. The increasing interest in bulk semiconducting iron disilicide, β-FeSi 2 , is due to the advantages of its high thermoelectric power, high absorption coefficient (higher than 10 5  cm −1 above 1.0 eV) and direct band gap of 0.85 eV. The thermoelectric material is suitable for active component applications such as in light detectors, near-infrared sources, photovoltaic application and optical fiber communication. Powders of pure electrolytic iron and silicon were mechanically alloyed in a Cryo mill for various periods viz. 4, 6 and 8 h. As-milled powders were compacted at 700 MPa and the compacts were then subjected to different heat treatment cycles under vacuum (10 −5 bar). The influence of variation in process parameters like milling period and sintering conditions on phase formation was studied. Traces of β-FeSi 2 phase appeared after Cryo milling for 6 h. The optimized condition to have nearly complete formation of the β-FeSi 2 phase, was found to be the one in which the material was Cryo milled for 6 h which was followed by sintering of compacts at 800 °C for 6 h under vacuum. Graphical Abstract XRD analysis of sintered compacts
ISSN:0972-2815
0975-1645
DOI:10.1007/s12666-016-0873-0