Magnetocaloric effect of Gd2O3 nanorods with 5% Eu-substitution

Hazarika, Samiran; Behera, P. Suchismita; Mohanta, Dambarudhar; Nirmala, R.

doi:10.1016/j.apsusc.2019.05.266

Cited by 24 publications

(6 citation statements)

References 23 publications

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“…The increase in cell volume is accompanied by an increase in the bond distances, thus, a decrease in the force constant and the corresponding wavenumber [62]. Moreover, the peak observed at ~ 355 cm -1 in the Raman spectrum of Ni/Gd2O3/NiO sample can be assigned to the Gd2O3 phase [63]. These results are in good agreement with XRD results [63].…”

Section: Resultssupporting

confidence: 85%

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Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

El-Maghrabi

Nada

Bekheet

et al. 2021

Journal of Colloid and Interface Science

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Cost-effective, active and stable electrocatalysts are pivotal to hydrogen production via electrocatalytic water splitting. Here we report on the preparation of novel nanofiber (NF) Ni/Gd2O3/NiO heterostructures by an electrospinning technique. The fabricated materials show high electrocatalytic performance for hydrogen evolution reaction (HER) with activities of onset potential at 89 mV, which is almost identical to that of platinum. The chemical and electronic properties of materials are successfully optimized in Ni/Gd2O3/NiO coaxial heterostructures; the NiO NF with Gd 3+ enhances remarkably its electrical conductivity and promotes HER reaction kinetics. It offers the distinct advantages of long-term durability and readiness for the integration into producing hydrogen via HER, affording better performance than benchmark Pt catalysts. The 2 successful fabrication of these metal oxides nanofibers and nanostructures may pave a new path for rational synthesis of efficient HER catalysts.

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Section: Resultssupporting

confidence: 85%

“…Moreover, the peak observed at ~ 355 cm -1 in the Raman spectrum of Ni/Gd2O3/NiO sample can be assigned to the Gd2O3 phase [63]. These results are in good agreement with XRD results [63]. The differences between the morphology of the three prepared fibers are illustrated by the scanning electron microscopy images presented in Fig.…”

Section: Resultssupporting

confidence: 84%

Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

El-Maghrabi

Nada

Bekheet

et al. 2021

Journal of Colloid and Interface Science

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“…The magnetic state of the Gd 2 O 3 nanotubes is superparamagnetic and exhibits anisotropic MCE at cryogenic temperature. Hazarika et al studied the magnetocaloric properties of Gd 2 O 3 nanorods with 5% Eu substitution [16] and observed the maximum entropy change value of ∼30.3 Jkg −1 K −1 at 6 K for 70 kOe field change. This value is quite large compared to other oxide materials.…”

Section: Introductionmentioning

confidence: 99%

Magnetocaloric properties of shape-dependent nanostructured Gd₂O₃ oxide particles

Neupane¹,

Casey²,

Sultana³

et al. 2023

Adv. Nat. Sci: Nanosci. Nanotechnol.

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Single-phase Gd2O3 nanostructures with different morphologies, such as nanoparticles, nanorods, nanospheres, and nanoplates, were synthesised. Gd2O3 1D nanorods and 2D nanoplate architectures were prepared via the hydrothermal method, while 3D hollow nanospheres were synthesised via homogeneous precipitation. The magnetic and magnetocaloric properties of Gd2O3 nanostructured particles were studied as functions of temperature and field. The material demonstrated typical paramagnetic behaviour in the measured temperature range of 3–300 K. The magnetic entropy change (−ΔS M ) was determined from the magnetic isotherms measured in the 3–38 K temperature range in the field up to 5 T. The maximum change in magnetic entropy Δ S M max value 11.2 J kg−1 K−1 for the nanoplate, 9.4 J kg−1 K−1 for the nanorod, 9.2 J kg−1 K−1 for the nanosphere, and 10.7 J kg−1 K−1 for the nanoparticle sample was observed at temperature 5 K for the magnetic field of 5 T. Owing to large Δ S M max , these Gd2O3 nanostructured particles would be considered promising materials for magnetic refrigeration at cryogenic temperatures.

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“…When the material exhibits a ferromagnetic-paramagnetic transition (second-order transition) during service, the refrigeration capacity can be also improved, since the disorder of the system increases in the transition of both, causing an increase of the total system entropy [3,10-12]. These types of transitions are commonly observed in alloys containing lanthanide elements (rare earths), due to their electronic configuration [13,14]. Alloys based on these elements have the best magnetocaloric response; however, these materials are very expensive, due to their obtaining and processing methods.The use of 3d transition elements has also attracted considerable attention, due to their unique physical properties and promising applications, such as magnetic field-induced shape memory effect, magnetic field-induced strain, magnetocaloric effect, and magnetoresistance [15][16][17][18].…”

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confidence: 99%

“…One advantage of the Cu-based alloys containing transition elements is that their magnetic behavior can be modified by changes in chemical composition or microstructure [12,24,26,27], in addition to the lower cost compared to rare earths [13,14,28]. Thermal treatments may also cause microstructural changes in Cu-based alloys, offering the possibility to modify their magnetic behavior.…”

mentioning

confidence: 99%

Effect of Quenching and Normalizing on the Microstructure and Magnetocaloric Effect of a Cu–11Al–9Zn Alloy with 6.5 wt % Ni–2.5 wt % Fe

et al. 2019

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First-order phase transitions (FOPT) and second-order phase transitions (SOPT) are commonly observed in Cu alloys containing lanthanide elements, due to their electronic configuration, and have an important effect on the optimization of their magnetocaloric effect (MCE). Alloys containing rare earths have the best magnetocaloric response; however, these elements are very expensive, due to their obtaining and processing methods. The present work reports the effect of using 3d transition elements and thermal treatments on the microstructure and MCE of Cu-11Al-9Zn alloys with 6.5 wt % Ni and 2.5 wt % Fe. It was found that thermal treatments of quenching and normalizing, as well as the use of Ni and Fe, have an important influence on both the resulting phases and MCE of the investigated alloy. MCE was calculated indirectly from the change in the magnetic entropy (-∆S m ) under isothermal conditions, using Maxwell´s relation; it was found that samples subjected to normalizing presented a higher magnetocaloric effect than samples with quenching, which was related to the greater disorder in the alloy, due to the coexistence of β 1 + β phases. Magnetochemistry 2019, 5, 48 2 of 12The entropy of such a system can be considered as the sum of two contributions: the entropy related to magnetic ordering and the entropy related to the temperature of the system. Application of a magnetic field will order the magnetic moments comprising the system, which are disordered by the thermal agitation energy, and consequently, the entropy depending on the magnetic ordering (the magnetic entropy, S m ) will be lowered. If a magnetic field is applied under adiabatic conditions, when any heat exchange with the surroundings is absent, then the entropy related to the temperature should increase in order to maintain constant the total entropy of the system constant. Increasing this entropy implies that the system heats up and increases its temperature [5].Unlike conventional refrigeration, magnetic refrigeration (MR) does not use gases that can contribute to the global heating and the deterioration of the ozone layer. However, so far only a few prototype refrigeration machines have been presented worldwide, and there are still many scientific and technological challenges to overcome [6,7]. While in conventional refrigeration a fluid undergoes compression/evaporation processes, causing a change in the temperature of the system, MR is based on a magnetization/demagnetization process. Therefore, the efficiency of the equipment used in MR depends strongly on the magnetic behavior of the solid refrigerant [8,9]. MCE can be obtained by promoting first-order transitions (for example, the martensitic transformation) due to a high crystal lattice disorder, which results in an increase of the total system entropy that leads to better cooling capacity [9]. When the material exhibits a ferromagnetic-paramagnetic transition (second-order transition) during service, the refrigeration capacity can be also improved, since the disorder of the system increases ...

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Magnetocaloric effect of Gd2O3 nanorods with 5% Eu-substitution

Cited by 24 publications

References 23 publications

Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

Magnetocaloric properties of shape-dependent nanostructured Gd₂O₃ oxide particles

Effect of Quenching and Normalizing on the Microstructure and Magnetocaloric Effect of a Cu–11Al–9Zn Alloy with 6.5 wt % Ni–2.5 wt % Fe

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Magnetocaloric effect of Gd2O3 nanorods with 5% Eu-substitution

Cited by 24 publications

References 23 publications

Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

Coaxial nanofibers of nickel/gadolinium oxide/nickel oxide as highly effective electrocatalysts for hydrogen evolution reaction

Magnetocaloric properties of shape-dependent nanostructured Gd2O3 oxide particles

Effect of Quenching and Normalizing on the Microstructure and Magnetocaloric Effect of a Cu–11Al–9Zn Alloy with 6.5 wt % Ni–2.5 wt % Fe

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Magnetocaloric properties of shape-dependent nanostructured Gd₂O₃ oxide particles