Abnormal conductivity behavior in porous lead telluride films

Lead telluride is an important semiconductor of many applications. Many Investigators showed that there are anamolous descripancies in most of the electrophysical properties of PbTe polycrystalline thin films on annealing. X-Ray and electron diffraction studies are being undertaken in the present work in order to explain the cause of this anamolous behaviour.Figures 1-3 show the electron diffraction of the unheated, heated in air at 100°C and heated in air at 250°C respectively of a 300°A polycrystalline PbTe thin film. It can be seen that Fig. 1 is a typical [100] projection of a face centered cubic with unmixed (hkl) indices. Fig. 2 shows the appearance of faint superlattice reflections having mixed (hkl) indices. Fig. 3 shows the disappearance of thf superlattice reflections and the appearance of polycrystalline PbO phase superimposed on the [l00] PbTe diffraction patterns. The mechanism of this three stage process can be explained on structural basis as follows :

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Revisiting the thermoelectric properties of lead telluride

Materials Today Energy ◽

10.1016/j.mtener.2021.100713 ◽

2021 ◽

pp. 100713

Author(s):

Pradeep Kumar Sharma ◽

T.D. Senguttuvan ◽

Vijay Kumar Sharma ◽

Sujeet Chaudhary

Keyword(s):

Thermoelectric Properties ◽

Lead Telluride

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An interpretation on the thermodynamic properties of liquid Pb–Te alloys

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0068 ◽

2020 ◽

Vol 39 (1) ◽

pp. 297-303

Author(s):

Toru Akasofu ◽

Masanobu Kusakabe ◽

Shigeru Tamaki

Keyword(s):

Thermodynamic Properties ◽

Electron Affinity ◽

Ionization Energy ◽

Narrow Band ◽

Structural Information ◽

Lead Telluride ◽

Liquid Lead ◽

Metallic State ◽

Ternary Solution ◽

Conduction Electrons

AbstractThe bonding character of liquid lead telluride \text{PbTe} is thermodynamically investigated in detail. Its possibility as an ionic melt composed of cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} is not acceptable, by comparing the ionization energy of \text{Pb} atom, electron affinity of \text{Te} atom and the ionic bonding energy due to the cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} with the help of structural information. Solid lead telluride PbTe as a narrow band gap semiconductor might yield easily the overlapping of the tail of valence band and that of conduction one. And on melting, it becomes to an ill-conditioned metallic state, which concept is supported by the electrical behaviors of liquid Pb–Te alloys observed by the present authors. As structural information tells us about the partial remain of some sorts of covalent-type mono-dipole and poly-dipole of the molecule \text{PbTe}, all systems are thermodynamically explained in terms of a mixture of these molecules and cations {\text{Pb}}^{4+} and {\text{Te}}^{2+} and a small amount of the conduction electrons are set free from these elements based on the ternary solution model.

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Heat transport through propagon-phonon interaction in epitaxial amorphous-crystalline multilayers

Communications Physics ◽

10.1038/s42005-021-00653-w ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Takafumi Ishibe ◽

Ryo Okuhata ◽

Tatsuya Kaneko ◽

Masato Yoshiya ◽

Seisuke Nakashima ◽

...

Keyword(s):

Group Velocity ◽

Density Of States ◽

Heat Dissipation ◽

Lattice Mismatch ◽

Lead Telluride ◽

Amorphous Layer ◽

Interface Layer ◽

Phonon Transport ◽

Nanoscale Systems ◽

Phonon Group Velocity

AbstractManaging heat dissipation is a necessity for nanoscale electronic devices with high-density interfaces, but despite considerable effort, it has been difficult to establish the phonon transport physics at the interface due to a “complex” interface layer. In contrast, the amorphous/epitaxial interface is expected to have almost no “complex” interface layer due to the lack of lattice mismatch strain and less associated defects. Here, we experimentally observe the extremely-small interface thermal resistance per unit area at the interface of the amorphous-germanium sulfide/epitaxial-lead telluride superlattice (~0.8 ± 4.0 × 10‒9 m2KW−1). Ab initio lattice dynamics calculations demonstrate that high phonon transmission through this interface can be predicted, like electron transport physics, from large vibron-phonon density-of-states overlapping and phonon group velocity similarity between propagon in amorphous layer and “conventional” phonon in crystal. This indicates that controlling phonon (or vibron) density-of-states and phonon group velocity similarity can be a comprehensive guideline to manage heat conduction in nanoscale systems.

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Conductivity behavior of BaZr0.9Dy0.1O3−δ

Solid State Ionics ◽

10.1016/j.ssi.2017.11.010 ◽

2018 ◽

Vol 314 ◽

pp. 25-29 ◽

Cited By ~ 3

Author(s):

S. Ricote ◽

L. Krishna ◽

W.G. Coors ◽

J.R. O'Brien

Keyword(s):

Conductivity Behavior

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Conductivity Behavior of Salt Deposits on the Surface of Engineered Barrier Materials for the Potential High-Level Nuclear Waste Repository at Yucca Mountain, Nevada

MRS Proceedings ◽

10.1557/proc-824-cc1.4 ◽

2004 ◽

Vol 824 ◽

Cited By ~ 3

Author(s):

Lietai Yang ◽

Miriam R. Juckett ◽

Roberto T. Pabalan

Keyword(s):

Electrical Conductance ◽

Yucca Mountain ◽

Nuclear Waste Repository ◽

Conductivity Measurements ◽

Barrier Materials ◽

Salt Mixtures ◽

High Level Nuclear Waste ◽

Waste Repository ◽

High Level ◽

Conductivity Behavior

AbstractThe electrical conductance or conductivity of three salt mixtures, Na-K-Cl-NO3, Ca-K-Cl and Ca-Na-Cl, were measured at 25, 50 and 70°C [77, 122, and 158 °F] as a function of relative humidity (RH). Mutual deliquescence and efflorescence RH (MDRH and MERH) values were determined based on the conductivity measurements. It was found that the conductivity of the three salt mixtures started to increase at RH values that are approximately 40 % of their MDRH and increased by 1to 2 orders of magnitude just before reaching the MDRH. At the MDRH, a significant increase in conductivity was observed. The MDRH and MERH for the Ca-K-Cl and Ca-Na-Cl mixtures were found to be approximately 15 % in the temperature range of 50 to 70 °C [122 to 158 °F]. The MDRH and MERH for the Na-K-Cl-NO3system were found to be approximately 54 % at 50 °C [122 °F] and decreased significantly with an increase in temperature.

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