Understanding the Seebeck coeﬃcient of LaNiO3 compound in the temperature range 300-620 K

Abstract Transition metal oxides have been attracted much attention in thermoelectric community from the last few decades. In the present work, we have synthesized LaNiO3 by a simple solution combustion process. To analyze the crystal structure and structural parameters we have used Rietveld reﬁnement method wherein FullProf software is employed. The room temperature x-ray diffraction indicates the rhombohedral structure with space group R 3 c (No. 167). The refined values of lattice parameters are a = b = c = 5.4071 Å. Temperature dependent Seebeck coeﬃcient (S) of this compound has been investigated by using experimental and computational tools. The measurement of S is conducted in the temperature range 300-620 K. The measured values of S in the entire temperature range have negative sign that indicates n-type character of the compound. The value of S is found to be ∼ -8 µV/K at 300 K and at 620 K this value is ∼ -12 µV/K. The electronic structure calculation is carried out using DFT+U method due to having strong correlation in LaNiO3. The calculation predicts the metallic ground state of the compound. Temperature dependent S is calculated using BoltzTraP package and compared with experiment. The best matching between experimental and calculated values of S is observed when self-interaction correction is employed as double counting correction in spin-polarized DFT + U (= 1 eV) calculation. Based on the computational results maximum power factors are also calculated for p-type and n-type doping of this compound.

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Variation of structural parameters in dimethylammonium manganese formate [(CH3)2NH2]Mn(HCOO)3 by substitution of transition metals (M = Zn, Co and Ni): by powder XRD method

Powder Diffraction ◽

10.1017/s0885715619000307 ◽

2019 ◽

Vol 34 (2) ◽

pp. 124-129

Author(s):

D. Sornadurai ◽

R. M. Sarguna ◽

V. Sridharan

Keyword(s):

Structural Parameters ◽

Metal Organic Framework ◽

Rhombohedral Structure ◽

Transition Elements ◽

X Ray Diffraction ◽

Ionic Radii ◽

X Ray ◽

Refinement Method ◽

Metal Organic ◽

Xrd Method

Variation of structural parameters of dimethylammonium manganese formate [(CH3)2NH2]Mn[(HCOO)3] upon substitution by the transition elements Zn, Co, and Ni is studied by powder X-ray diffraction (PXRD) technique. These metal–organic framework (MOF) crystals were grown by solvothermal method. The PXRD patterns of all MOFs exhibited rhombohedral structure. PXRD patterns of MOFs were analyzed using Rietveld refinement method. While the parent Mn-MOF and Mn0.9Zn0.1MOF are found to have similar structural parameters, Co and Ni substituted Mn-MOFs have smaller structural parameters than that of parent Mn-MOF. The reason for this variation in the lattice parameters is explained based on the Shannon ionic radii.

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The Effect of A Graded in Profile on the Figure of Merit of PbTe

MRS Proceedings ◽

10.1557/proc-545-513 ◽

1998 ◽

Vol 545 ◽

Cited By ~ 6

Author(s):

Z. Dashevsky ◽

S. Shusterman ◽

A. Horowitz ◽

M. P. Dariel

Keyword(s):

Seebeck Coefficient ◽

Carrier Concentration ◽

Concentration Profile ◽

External Source ◽

Charge Carrier Concentration ◽

Deep Impurity ◽

Temperature Range ◽

Fermi Level Pinning ◽

Type Character ◽

Set Up

AbstractThe present study was aimed at demonstrating the possibility of producing a graded charge carrier concentration in a PbTe crystal by taking advantage of the concentration profile that is set up by the diffusion of In from an external source. Doping by indium generates deep impurity levels lying close to the edge of the conduction band. The Fermi level pinning effect and the electron population of the In impurity levels, which reduces the minority carrier concentration at elevated temperature, significantly improve the thermoelectric behavior of the resulting material. The penetration profiles of In, originating from an external gaseous or liquid source, were determined using Seebeck coefficient measurements in p- and n-type PbTe crystals. In the p-type crystal, the Seebeck coefficient changed sign as the In concentration induced a change from p-type to n-type character. The thermovoltage of a PbTe crystal in which an In concentration profile, generated by In diffiusing from a gaseous source had been established, was determined in the 50 to 430 °C temperature range. The constant Seebeck coefficient that was observed over the whole temperature range provides the experimental support for the underlying premises of this study.

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Unusually High Seebeck Coefficient Arisen from the Temperature-dependent Carrier Concentration in PbSe-AgSbSe2 Alloys

Journal of Materials Chemistry C ◽

10.1039/d1tc04158d ◽

2021 ◽

Author(s):

Xuemei Wang ◽

Gang Wu ◽

Jianfeng Cai ◽

Qiang Zhang ◽

Junxuan Yang ◽

...

Keyword(s):

Temperature Gradient ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

Wide Temperature Range ◽

Induced Voltage ◽

Temperature Dependent ◽

Temperature Range ◽

High Seebeck Coefficient

Seebeck coefficient describes the temperature gradient induced voltage in thermoelectrics. Usually, to obtain a high Seebeck coefficient within a wide temperature range is difficult, as it is limited by the...

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Nanomaterial Preparations by Microwave-Assisted Solution Combustion Method and Material Properties of SnO2 Powder - A Status Review

Materials Science Forum ◽

10.4028/www.scientific.net/msf.671.69 ◽

2011 ◽

Vol 671 ◽

pp. 69-120 ◽

Cited By ~ 1

Author(s):

L.C. Nehru ◽

V. Swaminathan ◽

M. Jayachandran ◽

C. Sanjeeviraja

Keyword(s):

Structural Parameters ◽

Combustion Process ◽

Average Crystallite Size ◽

Combustion Method ◽

Solution Combustion ◽

Xrd Pattern ◽

Microwave Assisted ◽

Heat Treated ◽

Sno2 Sample ◽

Crystal Density

A nanocrystalline tin oxide (SnO2) powders have been prepared by a simple, low-temperature initiated, self-propagating and gas producing by microwave-assisted solution combustion process. The effects of temperature on crystalline phase formation and particle size of nanocrystalline SnO2 and its structure have been investigated. It is observed that heat-treated upto 800°C shows tetragonal phase SnO2. It was observed that the average crystallite size of the annealed SnO2 samples is in the range 9 - 43 nm through controlled heat treatment process. The crystal density of the as-prepared powder is 5.850g cm-3 where as the bulk density is 6.998 g cm−3. The microstructure and morphology were studied by scanning electron microscope (SEM) and HRTEM it is interesting to note that as-prepared SnO2 sample are almost spherical in shape and average agglomerate crystal size of 0.2 – 0.4 μm with increase in calcination temperature, the samples become better morphology than the as-prepared sample. The crystallographic parameters were refined by XRD pattern and Rietveld refinement using TOPAS-3 and Diamond software was used to construct the structural parameters.

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Seebeck Scanning Microprobe for Thermoelectric FGM

Materials Science Forum ◽

10.4028/www.scientific.net/msf.492-493.587 ◽

2005 ◽

Vol 492-493 ◽

pp. 587-592 ◽

Cited By ~ 15

Author(s):

D. Platzek ◽

G. Karpinski ◽

Cestmir Drasar ◽

Eckhard Müller

Keyword(s):

Seebeck Coefficient ◽

Conversion Efficiency ◽

Temperature Difference ◽

Current Flow ◽

Electrical Potential ◽

Large Temperature ◽

Voltage Response ◽

Temperature Dependent ◽

Temperature Range ◽

Additional Option

The FGM principle plays an important role in enhancing the efficiency of thermoelectric devices. While a thermoelectric generator (TEG) is typically operating in a large temperature difference, attractive conversion efficiency of a particular semiconductor is restricted to a small temperature range. Hence, when employing a semiconductor with its highest possible efficiency at the respective temperature in the internal temperature field along a stacked TEG, the overall conversion efficiency of the device may be considerably enhanced. Similarly, the FGM principle can be employed for linearization of thermal sensors. The output voltage (response) of the sensor is proportional to the Seebeck coefficient of the material the sensor is made of. Since the Seebeck coefficient is strongly temperature-dependent, the sensor response is not linear with temperature. However, combining in a stack two or more semiconductors which temperature dependence of the Seebeck coefficient are complementary to each other, results in a sensor with linear response (i.e. its output is proportional to the temperature difference, or heat flux, respectively.) Stacking of several materials to each other or grading a semiconducting sample requires a technique which can scan the Seebeck coefficient profiles S(x) along the stack. Accordingly a Seebeck micro-probe technique has been developed for scanning the surface of a sample monitoring S with a resolution of down to 10 µm within the temperature range from -15°C to 60°C. An additional option of such a device is the scanning of the electrical potential along the stack under current flow [1]. Thus, related experimental data on the local profiles of the electrical conductivity and Seebeck coefficient along the stack (or continuously graded FGM) will be available. The apparatus has been automated so that extended areas may be scanned providing two-dimensional images. Additionally, several samples can be scanned in one automatic run.

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Thermoelectric properties of In-filled and Te-doped CoSb3 prepared by high-pressure and high-temperature

Modern Physics Letters B ◽

10.1142/s0217984915500955 ◽

2015 ◽

Vol 29 (19) ◽

pp. 1550095 ◽

Cited By ~ 1

Author(s):

Le Deng ◽

Li Bin Wang ◽

Jie Ming Qin ◽

Tao Zheng ◽

Jing Ni ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

High Pressure ◽

High Temperature ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Temperature Dependent ◽

Synthesis Time ◽

Temperature Range

A novel chemical alloying method of high-pressure and high-temperature (HPHT) has been used for the synthesis of bulk-skutterudite [Formula: see text]. Through HPHT method, the synthesis time has been shortened from a few days to 30[Formula: see text]min. The samples of [Formula: see text] skutterudites were synthesized at 1.8–3.3[Formula: see text]GPa. We have studied the phase, the microstructure, and the temperature-dependent thermoelectric properties. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured in the temperature range of 295–673[Formula: see text]K. As we expected, the thermal conductivity of sample [Formula: see text] decreased with the increase of the synthetic pressure. A maximal ZT of 0.64 was achieved for the [Formula: see text] synthesized at 1.8[Formula: see text]GPa at 673[Formula: see text]K. These results revealed that HPHT method may be helpful for optimizing electrical conductivity and thermal conductivity in a comparatively independent way.

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Adsorption Characteristics of Reactive Blue onto Magnetic Ni0.7Co0.3Fe2O4 Nanoparticles Prepared via Alcohol-Solution Combustion Process

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.16932 ◽

2020 ◽

Vol 20 (2) ◽

pp. 957-964

Author(s):

Da-Wei He ◽

Zhou Wang

Keyword(s):

Combustion Process ◽

Alcohol Solution ◽

Solution Combustion ◽

Adsorption Characteristics ◽

Solution Combustion Process

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Empirical Model With Excellent Statistical Properties for Describing Temperature-Dependent Developmental Rates of Insects and Mites

Annals of the Entomological Society of America ◽

10.1093/aesa/saw098 ◽

2017 ◽

Vol 110 (3) ◽

pp. 302-309 ◽

Cited By ~ 20

Author(s):

David A. Ratkowsky ◽

Gadi V. P. Reddy

Keyword(s):

Nonlinear Regression ◽

Empirical Model ◽

Minimum Variance ◽

Statistical Properties ◽

Parameter Estimates ◽

Regression Equations ◽

Temperature Dependent ◽

Temperature Range ◽

Least Squares Estimators ◽

Development Rates

Abstract Previous empirical models for describing the temperature-dependent development rates for insects include the Briére, Lactin, Beta, and Ratkowsky models. Another nonlinear regression model, not previously considered in population entomology, is the Lobry–Rosso–Flandrois model, the shape of which is very close to that of the Ratkowsky model in the suboptimal temperature range, but which has the added advantage that all four of its parameters have biological meaning. A consequence of this is that initial parameter estimates, needed for solving the nonlinear regression equations, are very easy to obtain. In addition, the model has excellent statistical properties, with the estimators of the parameters being “close-to-linear,” which means that the least squares estimators are close to being unbiased, normally distributed, minimum variance estimators. The model describes the pooled development rates very well throughout the entire biokinetic temperature range and deserves to become the empirical model of general use in this area.

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