TY - CONF TI - Thermopower, electrical and Hall conductivity of undoped and doped iron disilicide single crystals AB - 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. AU - "Heinrich, A" AU - "Behr, G" AU - "Griessmann, H" AU - "Teichert, S" AU - "Lange, H" KW - "30 DIRECT ENERGY CONVERSION" KW - "36 MATERIALS SCIENCE" KW - "SEEBECK EFFECT" KW - "THERMOELECTRIC PROPERTIES" KW - "HALL EFFECT" KW - "IRON SILICIDES" KW - "SEMICONDUCTOR MATERIALS" KW - "THERMOELECTRIC MATERIALS" KW - "CRYSTAL DOPING" KW - "POLYCRYSTALS" KW - "MONOCRYSTALS" KW - "COMPARATIVE EVALUATIONS" DO - https://doi.org/ UR - PB - Materials Research Society, Warrendale, PA (US) CY - United States PY - 1997 DA - 1997-07-01 LA - English J2 - [] VL - C1 - Inst. fuer Festkoerper- und Werkstofforschung, Dresden (DE) C2 - Bundesministerium fuer Forschung und Technologie C3 - C4 - C5 - Materials Research Society, 506 Keystone Drive, Warrendale, PA 15086 (US); $71.00. Prices may become outdated. L3 - 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. ER -