Interparticle interaction effects on the magnetocaloric properties of γ-Fe2O3 nanoparticles dispersed in polyvinyl alcohol

Elouafi, A.; Moubah, R.; Derkaoui, S.; Tizliouine, A.; Cherkaoui, R.; Bendani, A.; Lassri, H.

doi:10.1007/s00339-019-2533-9

Cited by 12 publications

(4 citation statements)

References 37 publications

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“…Similar concept was recently studied by Elouafi et al . 13 where the effect of the change in the interparticle distance on the value of −Δ S was discussed. In this work, as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…In the last decade, it is possible to note a rapidly growing interest of the scientific community in the research related to applications involving the use of magnetic nanoparticles 1–18 . Among these studies, a particular attention has been devoted to the magnetocaloric property of the ultra-small nanoparticles (smaller than 50 nm) used for cooling purposes as discussed in the literature 2–6,9,11–13,15,17,19,20 .…”

Section: Introductionmentioning

confidence: 99%

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Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Dudek

Wolak

et al. 2019

Sci Rep

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Through the use of the Monte Carlo simulations utilising the mean-field approach, we show that a dense assembly of separated ultra-small magnetic nanoparticles embedded into a non-magnetic deformable matrix can be characterized by a large isothermal magnetic entropy change even upon applying a weak magnetic field with values much smaller than one Tesla. We also show that such entropy change may be very significant in the vicinity of the room temperature which effect normally requires an application of a strong external magnetic field. The deformable matrix chosen in this work as a host for magnetic nanoparticles adopts a thin film form with a large surface area to volume ratio. This in turn in combination with a strong magneto-volume coupling exhibited by this material allows us to show its suitability to be used in the case of a variety of applications utilising local cooling/heating such as future magnetic refrigerants.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Dudek

Wolak

et al. 2019

Sci Rep

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show abstract

“…Where β is the peak width at half-maximum intensity, θ is the peak position, k is a constant equal to 0.94, λ is the wavelength of the radiation and D is the crystallite size in (nm). The value of β was calculated using Fullprof 8.0 [20][21][22][23]. We can see that the size of the crystallites decreases significantly with the concentration of Ca indicating that calcium doping also inhibits the growth of TiO 2 crystallites due to the lattice stress introduced by the different size between Ca ions R(Ca 2 + ) = 0.99 Å) and Ti 4 + ions R(Ti 4 + ) = 0.605 Å) [24].…”

Section: Kmentioning

confidence: 99%

Enhancement of structural, linear and non-linear optical properties of Ti_1−xCa_2xO₂ solid solutions

Ezairi¹,

Elouafi²,

Lmai³

et al. 2022

Phys. Scr.

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Structural and morphological analyses of the Ti1-xCa2xO2 solid solutions and their complete linear and non-linear optical properties were investigated. Ti1-xCa2xO2 (0≤x≤0.5) powders were successfully synthesized via solid-state reaction route. The XRD patterns confirmed that the pure and doped samples exhibited anatase TiO2 phase. The crystallite size of TiO2 decreased to 82 nm after Ca doping. Furthermore, the dislocation density and lattice deformation are increased with increasing calcium concentration. SEM analysis revealed that Ti1-xCa2xO2 (0≤x≤0.5) powders have a granular structure and with doping, atom aggregations take on softer shapes. Energy dispersive x-ray Analysis (EDX) showed the appropriate composition for the ions depicted in the structure. Using spectrophotometric data, linear and nonlinear optical parameters were obtained and associated with the Ca content. The band gap of TiO2 has shifted from 3.1 to 2.8 eV with dopant concentration. As the percentage of Ca increased, the dielectric constant and optical conductivity also increased. The dispersion energy, plasma frequency, non-linear refractive index and Sellmeier’s parameters were also calculated and discussed with respect to Ca doping. The optical results obtained revealed the potential of the

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“…Magnetic refrigeration based on the magnetocaloric effect (MCE) is a promising alternative compared to the conventional gas compression-expansion technique [1][2][3][4][5][6][7][8]. The magnetocaloric effect of materials has been widely investigated experimentally and theoretically in order to better understand the fundamental physical properties of these materials [9][10][11][12][13][14][15][16][17][18]. According to the literature, materials with a high capacity for refrigerating (RCP) at low temperatures are preferred, particularly in spatial sciences, industrial refrigeration, and the liquefaction industry [19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Structural, magnetic and magnetocaloric effect of pyrochlore iridate Er₂Ir₂O₇

et al. 2023

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The structural, morphological, magnetic and magnetocaloric properties of Er2Ir2O7 are investigated. The X-ray diffraction analysis showed that Er2Ir2O7 has a cubic structure with the Fđ3m space group. Using Williamson-Hall (W-H) plot, the crystallite size was found to be smaller than that obtained from the SEM image. Magnetic measurements revealed a weak ferromagnetic transition at TC =140K, caused by the appearance of magnetic order of the Ir moments. ΔT (temperature at full width of half maxima) was estimated to be 27K and 40K for magnetic field changes of 40 kOe and 50 kOe, corresponding to the relative cooling power (RCP) values of 98 J/kg and 128 J/kg, respectively. Temperature-averaged Entropy Change (TEC) was calculated for all applied magnetic fields, and found to be slightly lower than (-∆S_M^max) values, indicating less hysteresis loss in the compound Er2Ir2O7 during the magnetic transition. This study provides a new pyrochlore material for MCE magnetocaloric applications.

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Interparticle interaction effects on the magnetocaloric properties of γ-Fe2O3 nanoparticles dispersed in polyvinyl alcohol

Cited by 12 publications

References 37 publications

Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Enhancement of structural, linear and non-linear optical properties of Ti_1−xCa_2xO₂ solid solutions

Structural, magnetic and magnetocaloric effect of pyrochlore iridate Er₂Ir₂O₇

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Interparticle interaction effects on the magnetocaloric properties of γ-Fe2O3 nanoparticles dispersed in polyvinyl alcohol

Cited by 12 publications

References 37 publications

Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature

Enhancement of structural, linear and non-linear optical properties of Ti1−xCa2xO2 solid solutions

Structural, magnetic and magnetocaloric effect of pyrochlore iridate Er2Ir2O7

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Product

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Enhancement of structural, linear and non-linear optical properties of Ti_1−xCa_2xO₂ solid solutions

Structural, magnetic and magnetocaloric effect of pyrochlore iridate Er₂Ir₂O₇