The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
D. T. Morelli - One of the best experts on this subject based on the ideXlab platform.
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thermoelectric properties of rare earth ruthenium Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
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Thermoelectric properties of rare earth–ruthenium–Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
H. Kong - One of the best experts on this subject based on the ideXlab platform.
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thermoelectric properties of rare earth ruthenium Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
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Thermoelectric properties of rare earth–ruthenium–Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
Ctirad Uher - One of the best experts on this subject based on the ideXlab platform.
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thermoelectric properties of rare earth ruthenium Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
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Thermoelectric properties of rare earth–ruthenium–Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
Xun Shi - One of the best experts on this subject based on the ideXlab platform.
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thermoelectric properties of rare earth ruthenium Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
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Thermoelectric properties of rare earth–ruthenium–Germanium Compounds
Journal of Applied Physics, 2007Co-Authors: H. Kong, Xun Shi, Ctirad Uher, D. T. MorelliAbstract:We report our studies of the thermoelectric properties of a class of Compounds of composition R3Ru4Ge13 (R=Y, Dy, Ho, and Lu). Magnetization measurements show that the R ion is in the trivalent state in each of these Compounds. Each of these Compounds displays a semiconductorlike rise in electrical resistivity with decreasing temperature. The magnitude of the resistivity is much larger than typical metals and is similar to that of a heavily doped semiconductor or semimetal. The Seebeck coefficient is positive throughout the temperature range of 2–800K with room temperature values of approximately 40μVK−1. The lattice thermal conductivity is remarkably low and exhibits a very flat temperature dependence. This is consistent with the observed internal disorder associated with the cagelike structure of these Compounds. Cobalt substitution for ruthenium enhances the semiconductor character but does not improve the thermoelectric properties.
Brian M. Fish - One of the best experts on this subject based on the ideXlab platform.
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divalent Germanium and tin Compounds stabilized by sterically bulky p o po o ps o and pn o ligands synthesis and first insights into catalytic application to polyurethane systems
Organometallics, 2006Co-Authors: Alex Sergey Ionkin, William J. Marshall, Brian M. FishAbstract:A sterically bulky chelating phosphine, t Bu 2 P-CH 2 -C(CF 3 ) 2 OH (1), was shown to stabilize divalent tin and Germanium Compounds: M[-O-C(CF 3 ) 2 CH 2 P t Bu 2 ] 2 (6, M = Sn; 14, M = Ge). Oxidizing reagents, e.g., sulfur, pyridine-N-oxide, and 1-azidoadamantane, reacted with divalent tin 6 on the phosphorus ligands exclusively, preserving the divalent state of tin in the resultant Compounds Sn[-O-C(CF 3 ) 2 -CH 2 P(S) t Bu 2 ] 2 (7), Sn[-O-C(CF 3 ) 2 CH 2 P(O) t Bu 2 ] 2 (11) and Sn[-O-C(CF 3 ) 2 CH 2 P t Bu 2 ],[-O-C(CF 3 ) 2 -CH 2 P(N 3 -Adamantyl) t Bu 2 ] 2 (12). The divalent Germanium compound 14 was found to be more prone to oxidation to the tetravalent state. For example, the reaction with 1-azidoadamantane gave tetravalent Germanium Compounds Ge[-O-C(CF3) 2 CH 2 P(-) t Bu],[-O-C(CF 3 ) 2 CH 2 P(=N-) t Bu 2 ] (16) and [Adaman-tyl],[-O-C(CF 3 ) 2 CH 2 P(=N-)]Ge-O-Ge[-O-C(CF 3 ) 2 CH 2 P(tBu) 2 (=N-)],[Adamantyl] (17). A Ge-O-Ge bridge in 17 is very linear, with an angle Ge-O-Ge of 177.4(2)°. According to X-ray analyses the intramolecular M-P bond lengths are among the longest known for this kind of bonding: 3.228(4) A for P-Sn in 12 and 2.7585(12) A for P-Ge in 14. The divalent tin Compounds 6 and 7 were found to be efficient catalysts for the formation of polyurethanes. The divalent Germanium compound 14 was active in polyurethane formation, but it was an order of magnitude less active than corresponding tin analogue 6.
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Divalent Germanium and Tin Compounds Stabilized by Sterically Bulky P∧O, PO∧O, PS∧O, and PN∧O Ligands: Synthesis and First Insights into Catalytic Application to Polyurethane Systems†
Organometallics, 2006Co-Authors: Alex Sergey Ionkin, William J. Marshall, Brian M. FishAbstract:A sterically bulky chelating phosphine, t Bu 2 P-CH 2 -C(CF 3 ) 2 OH (1), was shown to stabilize divalent tin and Germanium Compounds: M[-O-C(CF 3 ) 2 CH 2 P t Bu 2 ] 2 (6, M = Sn; 14, M = Ge). Oxidizing reagents, e.g., sulfur, pyridine-N-oxide, and 1-azidoadamantane, reacted with divalent tin 6 on the phosphorus ligands exclusively, preserving the divalent state of tin in the resultant Compounds Sn[-O-C(CF 3 ) 2 -CH 2 P(S) t Bu 2 ] 2 (7), Sn[-O-C(CF 3 ) 2 CH 2 P(O) t Bu 2 ] 2 (11) and Sn[-O-C(CF 3 ) 2 CH 2 P t Bu 2 ],[-O-C(CF 3 ) 2 -CH 2 P(N 3 -Adamantyl) t Bu 2 ] 2 (12). The divalent Germanium compound 14 was found to be more prone to oxidation to the tetravalent state. For example, the reaction with 1-azidoadamantane gave tetravalent Germanium Compounds Ge[-O-C(CF3) 2 CH 2 P(-) t Bu],[-O-C(CF 3 ) 2 CH 2 P(=N-) t Bu 2 ] (16) and [Adaman-tyl],[-O-C(CF 3 ) 2 CH 2 P(=N-)]Ge-O-Ge[-O-C(CF 3 ) 2 CH 2 P(tBu) 2 (=N-)],[Adamantyl] (17). A Ge-O-Ge bridge in 17 is very linear, with an angle Ge-O-Ge of 177.4(2)°. According to X-ray analyses the intramolecular M-P bond lengths are among the longest known for this kind of bonding: 3.228(4) A for P-Sn in 12 and 2.7585(12) A for P-Ge in 14. The divalent tin Compounds 6 and 7 were found to be efficient catalysts for the formation of polyurethanes. The divalent Germanium compound 14 was active in polyurethane formation, but it was an order of magnitude less active than corresponding tin analogue 6.