Tuning optical and thermoelectric properties of LaCoO3: Partial substitution of La by isovalent Gd

Shanubhogue, U. Deepika; Pal, Anand; Rao, Ashok; Chattopadhyay, Saikat; Ashok, Anuradha; Davis, Nithya

doi:10.1016/j.jallcom.2023.168987

Cited by 4 publications

(1 citation statement)

References 61 publications

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“…The system un-doped LaCoO3 shows a large negative Seebeck coefficient at room temperature (|s| ˃ 200 µV/K) most probably due to a small amount of oxygen deficiency [32]; indicating a n-type conduction, and with increasing temperature becomes positive to 450 K. The partial replacement of ion Co by Ni (x=0.05) leads to a large positive Seebeck coefficient (|s| ˃ 600 µV/K) compared with LaCoO3 at room temperature, and decreases to up |s| ~ 150 µV/K (450 K) conserved the sign of coefficient indicative of p-type conduction. At high temperatures (T~450 K) the Seebeck coefficient decreases with increasing of temperature for both samples analyzed with values similar to those reported for polycrystalline samples of LaCoO3 [28,31,33,34].…”

Section: Thermoelectrical Propertiessupporting

confidence: 84%

Effect of Ni-Doping on Seebeck Coefficient of LaCoO<sub>3</sub> System

Echavarría,

Zapata,

Muñoz

et al. 2024

KEM

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The aim of this study is discussing the results achieved on undoped and Ni-doped bulk LaCoO3 samples synthesized by solid-state reaction. The crystal structures of the samples were analyzed by x – ray diffraction (XRD) and Rietveld refinement of the XRD patterns was used to test the quality of the samples, the results of this procedure confirmed a single phase of LaCo1-xNixO3 for (x=0 and 0.05) with rhombohedral crystal structure (space group :). The main interest in this class of materials is the possibility of improving the values of Seebeck coefficient and electrical resistivity through chemical doping. The Seebeck coefficient and electrical resistivity were investigated from room temperature (RT) to 450 K, near RT the LaCoO3 system showed a large negative Seebeck coefficient, but it changed to positive value with increasing temperature while the LaCo0.95Ni0.05O3 composition showed a positive Seebeck coefficient throughout all the temperature range. Hence, within this study the Ni substitution led to decrease the electrical resistivity of the samples to one order of magnitude as a result of the partial substitution of Co3+ in LaCoO3 by Ni2+. LaCoO3 was chosen for this thermoelectric test because cobalt oxides have extensive applications.

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Section: Thermoelectrical Propertiessupporting

confidence: 84%

Effect of Ni-Doping on Seebeck Coefficient of LaCoO<sub>3</sub> System

Echavarría,

Zapata,

Muñoz

et al. 2024

KEM

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Role of Bi/Te co-dopants on the thermoelectric properties of SnSe polycrystals: an experimental and theoretical investigation

Shankar,

Prabhu,

Ashok

et al. 2024

J Mater Sci

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A sustainable solution to the energy crisis may be found in thermoelectric materials and generators, capable of transforming thermal energy into electrical energy or vice versa. SnSe is one of the emerging thermoelectric materials with distinctive properties. The main advantages of this compound are earth-abundant, inexpensive, non-toxic and it is also known for its high thermoelectric performance. Here we prepared Bi/Te co-doped SnSe polycrystals; whereas, Bi and Te are added with different compositions such as (x = 0.0,0.02,0.04,0.06 and y = 0.03) in (Sn1-xBixSe1-YTeY) matrix by using the solid-state reaction method. XRD data confirms the samples belong to the orthorhombic crystal system with the Pnma space group. DFT calculations were used to see structural stability and electronic properties for pure and doped SnSe samples. Temperature-dependent semiconducting behavior of the samples has been demonstrated by electrical resistivity. The Seebeck coefficient, correlated with carrier concentration and mobility, validates the p-type behavior for the pristine samples and the n-type behavior for co-doped samples. The dominant behavior of phonon scattering has been demonstrated by thermal conductivity analysis. After co-doping there is decrement in total thermal conductivity was observed which 1.3 times lower than SnSe. A theoretical calculation was used to validate experimental results to estimate electrical properties, Seebeck coefficient, specific heat capacity, thermal conductivity, and power factor using Quantum espresso code with Boltzmann transport Equation. 4% Bi-doped sample displayed a significant increment in electrical conductivity and an enhanced Seebeck coefficient, which led to the power factor enhancement of approximately 2.0 times in contrast to the pristine sample and enhanced ZT of about 0.055 which is 3.43 times higher than the pristine SnSe. Graphical abstract

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Incorporation of copper in LaCoO3: modulating thermoelectric power factor for low- and mid-temperature thermoelectric applications

Rao,

Mukherjee

et al. 2023

J Mater Sci: Mater Electron

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In the present work, LaCoO3/ x wt% Cu (x = 0%, 5%, 10%, 15%, and 20%) samples were prepared using solid-state reaction method followed by conventional sintering. We have performed electrical and thermoelectric (TE) measurements on these samples both at low (100–310 K) as well as in mid (310–790 K) temperature range. X-ray diffraction (XRD) studies showed that the pristine LaCoO3 sample crystallized in a distorted rhombohedral structure with the space group $$R\stackrel{-}{3}c$$ R 3 - c . Interestingly, the addition of Cu resulted in two distinct phases viz. rhombohedral LaCoO3 and monoclinic CuO. Throughout the entire temperature range, the electrical resistivity of the samples decreased with temperature, which depicts the semiconducting behavior of the prepared samples. Furthermore, there is a crossover from negative to positive Seebeck coefficient for the pristine sample at 275 K, but all the copper-incorporated samples exhibited a positive Seebeck coefficient indicating holes as the majority charge carriers. It is found that, the sample with x = 10% exhibited the maximum power factor of about 99 µW/m K2 at 400 K, which is significantly higher than the pristine sample at the same temperature.

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Tuning optical and thermoelectric properties of LaCoO3: Partial substitution of La by isovalent Gd

Cited by 4 publications

References 61 publications

Effect of Ni-Doping on Seebeck Coefficient of LaCoO<sub>3</sub> System

Effect of Ni-Doping on Seebeck Coefficient of LaCoO<sub>3</sub> System

Role of Bi/Te co-dopants on the thermoelectric properties of SnSe polycrystals: an experimental and theoretical investigation

Incorporation of copper in LaCoO3: modulating thermoelectric power factor for low- and mid-temperature thermoelectric applications

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