Open Access. Powered by Scholars. Published by Universities.®
- File Type
Articles 1 - 4 of 4
Full-Text Articles in Physics
Structure Inhomogeneities, Shallow Defects, And Charge Transport In The Series Of Thermoelectric Materials K2bi8−Xsbxse13, Jeffrey S. Dyck, T. Kyratski, E. Hatzikraniotis, K. M. Paraskevopoulos, C. D. Malliakas, C. Uher, M. G. Kanatzidis
Structure Inhomogeneities, Shallow Defects, And Charge Transport In The Series Of Thermoelectric Materials K2bi8−Xsbxse13, Jeffrey S. Dyck, T. Kyratski, E. Hatzikraniotis, K. M. Paraskevopoulos, C. D. Malliakas, C. Uher, M. G. Kanatzidis
Jeffrey Dyck
The charge transport properties of the low-dimensional thermoelectric materials K2Bi8-xSbxSe13 (02Bi8-xSbxSe13 was analyzed on the basis of the classical semiconductor theory and discussed in the context of recent band calculations. The results suggest that the K2Bi8-xSbxSe13 materials possess coexisting domains with semimetallic and semiconducting characters whose ratio is influenced by the value of x and by local defects. The extent and relative distribution of these domains control the charge transport properties. Electron diffraction experiments performed on samples of K2Bi8-xSbxSe13 with x=1.6 show evidence for such domains by indicating regions with long range ordering of K+/Bi3+ atoms and regions with increased …
Preparation And Some Physical Properties Of Tetradymite-Type Sb2te3 Single Crystals Doped With Cds., P. LošŤÁK, Č. Drašar, A. Krejc ̆ Ova, L. Beneš, Jeffrey Dyck, W. Chen, C. Uher
Preparation And Some Physical Properties Of Tetradymite-Type Sb2te3 Single Crystals Doped With Cds., P. LošŤÁK, Č. Drašar, A. Krejc ̆ Ova, L. Beneš, Jeffrey Dyck, W. Chen, C. Uher
Jeffrey Dyck
Single crystals of Sb2Te3 doped with CdS were prepared by a modified Bridgman method from the elements Sb and Te of 5N purity and the CdS compound of 4.5N purity. Samples were characterized by X-ray diffraction and by measurement of reflectance in the plasma resonance frequency region at room temperature. Furthermore, we made measurements of temperature dependence of the electrical resistivity, Hall and Seebeck coefficients, and thermal conductivity in the temperature range of 4.2–300K. In the process of crystal growth, CdS dissociated and it was assumed that the Cd-atoms formed substitutional defects in the Sb-sublattice (CdSb′) while the S-atoms formed …
Characteriation Of Bulk, Polycrystalline Indium Nitride Grown Of Subatmospheric Pressures, Jeffrey Dyck, Kathleen Kash, Kwieseon Kim, Walter Lambrecht, Cliff Hayman, Alberto Argoitia, Michael Grossner, Willie Zhou, John Angus
Characteriation Of Bulk, Polycrystalline Indium Nitride Grown Of Subatmospheric Pressures, Jeffrey Dyck, Kathleen Kash, Kwieseon Kim, Walter Lambrecht, Cliff Hayman, Alberto Argoitia, Michael Grossner, Willie Zhou, John Angus
Jeffrey Dyck
Polycrystalline, wurtzitic indium nitride was synthesized by saturating indium metal with atomic nitrogen from a microwave plasma source. Plasma synthesis avoids the high equilibrium pressures required when molecular nitrogen is used as the nitrogen source. Two types of growth were observed: 1) small amounts of indium nitride crystallized from the melt during cooling and 2) hexagonal platelets formed adjacent to the In metal source on the crucible sides. The mechanism of this latter growth is not established, but may involve transport of indium as a liquid film. The crystals were characterized by electron diffraction, X-ray diffraction, elemental analysis, scanning electron …
Synthesis Of Bulk, Polycrystalline Gallium Nitride At Low Pressures, Alberto Argoitia, John Angus, Cliff Hayman, Long Wang, Jeffrey Dyck, Kathleen Kash
Synthesis Of Bulk, Polycrystalline Gallium Nitride At Low Pressures, Alberto Argoitia, John Angus, Cliff Hayman, Long Wang, Jeffrey Dyck, Kathleen Kash
Jeffrey Dyck
Bulk, polycrytalline gallium nitride was crystallized from gallium saturated with nitrogen obtained from a microwave electron cyclotron resonance source. The polycrystalline samples are wurtzitic and n-type. Well-faceted crystals give near-band-edge and yellow band photo-luminescence at both 10K and 300K. The results show that atomic nitrogen is an attractive alternative to high pressure molecular nitrogen for saturation of gallium with nitrogen for synthesis of bulk gallium nitride.