Thermopower, electrical and Hall conductivity of undoped and doped iron disilicide single crystals
The electrical transport properties of {beta}-FeSi{sub 2} single crystals have been investigated in dependence on the purity of the source material and on doping with 3d transition metals. The transport properties included are electrical conductivity, Hall conductivity and thermopower mainly in the temperature range from 4K to 300K. The single crystals have been prepared by chemical transport reaction in a closed system with iodine as transport agent. In undoped single crystals prepared with 5N Fe both electrical conductivity and thermopower depend on the composition within the homogeneity range of {beta}-FeSi{sub 2} which is explained by different intrinsic defects at the Si-rich and Fe-rich phase boundaries. In both undoped and doped single crystals impurity band conduction is observed at low temperatures but above 100K extrinsic behavior determined by shallow impurity states. The thermopower shows between 100K and 200K a significant phonon drag contribution which depends on intrinsic defects and additional doping. The Hall resistivity is considered mainly with respect to an anomalous contribution found in p-type and n-type single crystals and thin films. In addition doped single crystals show at temperatures below about 130K an hysteresis of the Hall voltage. These results make former mobility data uncertain. Comparison will be made between the transport properties of single crystals and polycrystalline material.
- Research Organization:
- Inst. fuer Festkoerper- und Werkstofforschung, Dresden (DE)
- Sponsoring Organization:
- Bundesministerium fuer Forschung und Technologie
- OSTI ID:
- 20014266
- Resource Relation:
- Conference: 1997 Materials Research Society Spring Meeting, San Francisco, CA (US), 03/31/1997--04/03/1997; Other Information: Single article reprints are available through University Microfilms Inc., 300 North Zeeb Road, Ann Arbor, Michigan 48106; PBD: 1997; Related Information: In: Thermoelectric materials -- New directions and approaches. Materials Research Society symposium proceedings, Volume 478, by Tritt, T.M.; Kanatzidis, M.G.; Lyon, H.B. Jr.; Mahan, G.D. [eds.], 359 pages.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Study of trap levels in β-Ga2O3 by thermoluminescence spectroscopy
CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions