Nonmonotonous Behavior of Temperature-Dependence of Plasma Frequency and Effect of a Local Instability of the PbTe:In,Ga Lattice

1997 ◽  
Vol 484 ◽  
Author(s):  
A. I. Belogorokihov ◽  
L. I. Belogorokhova ◽  
D. R. Khokhlov
Keyword(s):  
Temperature Dependence ◽  
Plasma Frequency ◽  
Lattice Structure ◽  
Lead Telluride ◽  
Far Infrared ◽  
Infrared Region ◽  
Anomalous Behavior ◽  
Local Instability ◽  
Impurity Centers ◽  
First Time

AbstractThe optical spectra of PbTe:In,Ga samples were studied in the Far Infrared region at temperatures T=11 K–3 50K. Anomalous behavior of the temperature dependence of the plasma frequency at 65K–80K was observed for the first time. This is explained by means of a model of localized changes in the lead telluride lattice structure near impurity centers.

scholarly journals Lead Telluride Doped with Au as a Very Promising Material for Thermoelectric Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Pantelija M. Nikolic ◽  
Konstantinos M. Paraskevopoulos ◽  
Triantafyllia T. Zorba ◽  
Zorka Z. Vasiljevic ◽  
Eleni Pavlidou ◽  
...  
Keyword(s):  
Electronic Transport ◽  
Room Temperature ◽  
Plasma Frequency ◽  
Lead Telluride ◽  
Far Infrared ◽  
Optical Parameters ◽  
High Quality ◽  
Free Carriers ◽  
Reflectivity Spectra

PbTe single crystals doped with monovalent Au or Cu were grown using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for all samples and plasma minima were registered. These experimental spectra were numerically analyzed and optical parameters were calculated. All the samples of PbTe doped with Au or Cu were of the “n” type. The properties of these compositions were analyzed and compared with PbTe containing other dopants. The samples of PbTe doped with only 3.3 at% Au were the best among the PbTe + Au samples having the lowest plasma frequency and the highest mobility of free carriers-electrons, while PbTe doped with Cu was the opposite. Samples with the lowest Cu concentration of 0.23 at% Cu had the best properties. Thermal diffusivity and electronic transport properties of the same PbTe doped samples were also investigated using a photoacoustic (PA) method with the transmission detection configuration. The results obtained with the far infrared and photoacoustic characterization of PbTe doped samples were compared and discussed. Both methods confirmed that when PbTe was doped with 3.3 at% Au, thermoelectric and electrical properties of this doped semiconductor were both significantly improved, so Au as a dopant in PbTe could be used as a new high quality thermoelectric material.

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Far Infrared ◽  
Infrared Region ◽  
Thz Radiation ◽  
The Real ◽  
Thz Range ◽  
The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

Hagen-Rubens relation beyond far-infrared region

2010 ◽  
Vol 90 (4) ◽  
pp. 44004 ◽  
Author(s):  
F. E. M. Silveira ◽  
S. M. Kurcbart
Keyword(s):  
Far Infrared ◽  
Infrared Region

scholarly journals Graphene-Based Plasmonic Tunable Dual-Band Bandstop Filter in the Far-Infrared Region

2018 ◽  
Vol 10 (6) ◽  
pp. 1-9 ◽  
Author(s):  
Yijun Cai ◽  
Kai Da Xu ◽  
Rongrong Guo ◽  
Jinfeng Zhu ◽  
Qing Huo Liu
Keyword(s):  
Far Infrared ◽  
Infrared Region ◽  
Dual Band ◽  
Bandstop Filter

TRANSPORT CHARACTERISTICS IN c-AXIS La2-xSrxCuO4 (LSCO) SINGLE CRYSTALS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 447-450
Author(s):  
SANG-JAE KIM ◽  
TAKESHI HATANO
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Critical Current ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Etching Method ◽  
First Time ◽  
Small Voltage

c-axis micro-bridges of La 2-x Sr x CuO 4 ( LSCO ) single crystals were fabricated by the focused-ion-beam (FIB) etching method. Small rectangular LSCO pieces were fabricated by cutting and grinding single crystals of underdoped LSCO of x=0.09. The size of LSCO single crystals between electrodes was cut to 20×40μm2 in ab-plane by using the FIB etching method. Superconductor-insulator-superconductor (SIS) like-branch structures on I-V curves of the LSCO stacks were observed for the first time. The branch structures exhibited voltage jumps of several tens mV in the range of from 1.7 K to 5 K with temperature dependence. When the temperature is changed from 5 K to 1.7 K , the critical current and the next branch split into a few of small voltage jumps with the intervals of several mV in the range of from 0.1 mV and 2.0 mV .

Dithiolium and diselenolium compounds of the transition metals

1969 ◽  
Vol 22 (1) ◽  
pp. 83 ◽  
Author(s):  
RL Martin ◽  
IM Stewart
Keyword(s):  
Transition Metals ◽  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
First Time

The preparations are reported of an extended series of compounds of the type ML2X4 where M is Mn, Fe, Co, or Ni; X is Cl or Br; and L is analytically identical with dithioacetylacetone. ��� Electronic, infrared, and Mossbauer spectra together with the temperature dependence of the magnetism (80-300�K) of these compounds establish-contrary to previous suggestions in the literature-that they should be properly formulated as tetrahalometallate salts of the 3,5- dimethyl-1,2-dithiolium cation. Simple salts of this cation (such as the iodide) have also been isolated. ��� During the course of this work salts (I- and [CoCl4]2-) of the hitherto unknown 3,5-dimethyl-1,2-diselenolium ion were synthesized and characterized for the first time.

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