Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
RSC Adv ; 14(16): 11121, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38590350

RESUMO

[This corrects the article DOI: 10.1039/D3RA90093B.][This corrects the article DOI: 10.1039/D1RA07059B.].

2.
Heliyon ; 10(1): e23848, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38192836

RESUMO

Pristine ZrO2 and doped with different concentrations of Copper (0-7 %) were synthesized using a sol-gel combustion route. Several advanced techniques like XRD, EDX, TEM, XPS, P.L., and UV-vis spectrophotometer have characterized the compositions. The XRD proved that all peaks matched with a tetragonal phase of ZrO2 without any impurities of other phases. An average crystallite size rises from 20 to 55 nm by increasing the concentrations of Copper. The elemental analysis was examined by EDX and confirmed the presence of Cooper, Zirconium, and Oxygen. The red shift was observed due to a decrease in the bandgap (5.5-4.01 eV) with increasing the Cu concentrations. From the analysis of photocatalysis of pure ZrO2 and different concentrations of Cu-doped ZrO2 for M.B., RHB, and mix of them. The increase in doping of Cu led to enhancing the performance of the removing MB from 35 to 80 %, however, the RHB degradation was from 42 to 81 % while the mix of M.B. and RHB reached 85 % with 7 % Cu-doping ZrO2.

4.
RSC Adv ; 12(7): 3935-3947, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35425461

RESUMO

We present a detailed study on the physical properties of La0.6Ba0.2Sr0.2Mn1-x Ni x O3 samples (x = 0.00, 0.05 and 0.1). The ceramics were fabricated using the sol-gel route. Structural refinement, employing the Rietveld method, disclosed a rhombohedral R3̄c phase. The magnetization vs. temperature plots show a paramagnetic-ferromagnetic (PM-FM) transition phase at the T C (Curie temperature), which decreases from 354 K to 301 K. From the Arrott diagrams M 2 vs. µ 0 H/M, we can conclude the phase transition is of the second order. Based on measurements of the isothermal magnetization around T C, the magnetocaloric effects (MCEs) have been calculated. The entropy maximum change (-ΔS M) values are 7.40 J kg-1 K-1, 5.6 J kg-1 K-1 and 4.48 J kg-1 K-1, whereas the relative cooling power (RCP) values are 232 J kg-1, 230 J kg-1 and 156 J kg-1 for x = 0.00, 0.05 and 0.10, respectively, under an external field (µ 0 H) of 5 T. Through these results, the La0.6Ba0.2Sr0.2Mn1-x Ni x O3 (0 ≤ x ≤ 0.1) samples can be suggested for use in magnetic refrigeration technology above room temperature. The electrical resistivity (ρ) vs. temperature plots exhibit a transition from metallic behavior to semiconductor behavior in the vicinity of T M-SC. The adiabatic small polaron hopping (ASPH) model is applied in the PM-semiconducting part (T > T MS). Throughout the temperature range, ρ is adjusted by the percolation model. This model is based on the phase segregation of FM-metal clusters and PM-insulating regions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...