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Microstructure and properties of laser interference crystallized amorphous FeSiB ribbon
摘要： The influence of Q-switched pulsed Nd:YAG laser interference heating, using 120 mJ of pulse energy and a variable number of consecutive pulses, on the microstructure and magnetic properties of amorphous Fe80Si11B9 alloy was examined. Microstructural analysis, using light, scanning and transmission electron microscopy, was complemented by results of M?ssbauer spectroscopy and measurement of magnetic properties (vibrating sample magnetometer). Periodically distributed crystallized micro-areas, *10 lm in diameter, in an amorphous matrix were produced by the treatments. Magnetization measurements showed that the as-cast ribbon and laser light irradiated samples are magnetically soft materials. The results lead to the conclusion that the dots corresponding to the laser modified regions exhibit a perpendicular magnetic anisotropy.
关键词： Laser interference heating,SEM,TEM,FeSiB amorphous alloy,Magnetic properties
更新于2025-11-14 17:04:02
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Tunable magnetic and fluorescent properties of Tb3Ga5O12 nanoparticles doped with Er3+, Yb3+, and Sc3+
摘要： In this study, we present the synthesis of Tb3Ga5O12 nanoparticles doped with Er3+, Yb3+, and Sc3+ ions, prepared using a co-precipitation method. These materials have well-defined magnetic-fluorescence properties. The effects of Yb3+ ion concentration on the structural characteristics, morphology, luminescence, and magnetic properties of the nanoparticles were investigated in detail using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, photoluminescence spectroscopy, and vibrating sample magnetometer measurements. Under 980-nm laser diode excitation, the nanoparticles displayed bright up-conversion luminescence, showing evidence of resonant energy transfer from the Yb3+ to Er3+ ions. Intense green and red emissions located at approximately 526, 548, and 656 nm were attributed to the radiant transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 of Er3+, respectively. These observations indicate that Tb3Ga5O12:Er3+, Yb3+, Sc3+ magnetic–fluorescent bifunctional nanoparticles are promising materials for use in bioimaging and magnetic bio-separation applications.
关键词： magnetic properties,lanthanide-doped materials,nanoparticles,rare-earth metal,terbium gallium garnet (Tb3Ga5O12),up-conversion luminescence
更新于2025-11-14 15:26:12
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A series of germanotungstate-based 3d-4f heterometallic compounds with visible-light induced photocatalytic, electrochemical and magnetic properties
摘要： A series of 3d-4f heterometallic germanotungstate dimers {[Cu(dap)(H2O)3][LnCu3(dap)3(OH)3(H2O)2(GeW11O39)]}·nH2O (Ln = SmⅢ, n = 11 (1), EuⅢ, n = 12 (2), GdⅢ, n = 10 (3) and TbⅢ, n = 13 (4); dap = 1, 2-diaminopropane) have been prepared under hydrothermal conditions and structurally characterized by IR, UV-Vis, XRD, and X-ray single-crystal diffraction. Compounds 1–4 are essentially isomorphic and display organic-inorganic hybrid dimeric structures consisting of [LnCu3(dap)3(OH)3(H2O)(GeW11O39)]2 4– with two supporting [Cu(dap)(H2O)3]2+ cations on both sides. The four compounds all exhibit the excellent photocatalytic activities to delaradation of methylene blue (MB) and rhodamine-B (RhB) under visible light irradiation in the presence of H2O2. Additionally, 1–4 displays an apparent electrocatalytic activity for the reduction of hydrogen peroxide. The variable-temperature magnetic studies show that the magnetic behaviours of 1, 2 and 4 are dominated by antiferromagnetic coupling interactions, while that of 3 is ferromagnetic interactions coexist along with antiferromagnetic interactions.
关键词： Photocatalytic properties,Lacunary polyoxometalates,magnetic properties,Crystal structure,Electrocatalytic properties,3d-4f Heterometallic compounds
更新于2025-09-23 15:23:52
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Magnetization and magnetic resonance in sol-gel derived polycrystalline BiFeO3 film
摘要： The structure and magnetic properties of polycrystalline BiFeO3 films grown on glass substrate using Sol-Gel technique have been investigated. X-ray diffraction (XRD) analysis revealed the average grain size of about 21 nm. The root mean square (RMS) surface roughness of about 50 nm has been obtained for the film by using scanning electron microscope (SEM) technique. Ferromagnetic resonance (FMR) studies showed the presence of macroscopic ferromagnetic magnetization and uniaxial out-of-plane magnetic anisotropy. The temperature dependences of the magnetization of BiFeO3 films registered in zero field cooling (ZFC) and field cooling (FC) regimes revealed a spin glass state. The average magnetic crystallite sizes obtained from the magnetizations studies coincide with the values revealed from the structural studies.
关键词： sol-gel technique,magnetic properties,magnetic materials,multiferroics
更新于2025-09-23 15:23:52
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Fascinating Physical Properties of 2D Hybrid Perovskite [(NH3)(CH2)7(NH3)]CuClxBr4?x, x?=?0, 2 and 4
摘要： The 2-D organic–inorganic hybrid perovskites of the formula [(NH3)(CH2)7(NH3)]CuClxBr4?x, x = 0, 2 and 4 were prepared by slow evaporation from ethanolic solution in stoichiometric ratio 1:1 (organic/inorganic). Microchemical analysis and x-ray diffraction (XRD) were used to confirm the formation of the presently investigated hybrids. Differential scanning calorimetry (DSC) indicated order–disorder transitions at T1 = 357 K, T2 = 388 K, and T3 = 398 K for x = 0, 2 and 4 of the three heptane diammonium Cu hybrid perovskites, respectively. These transitions are in good agreement with the electrical permittivity results at different frequencies and temperatures. Optical properties and estimated band gap energy reveal that the band gap energy decreases sharply with replacement of Cl ion by Br ion where the band gap energy of [(NH3)(CH2)7(NH3)]CuBr4, x = 0 (denoted 2C7CuBr) is 1.6 eV (brown color) and for [(NH3)(CH2)7(NH3)]CuCl4, x = 4 (denoted 2C7CuCl) is 2.6 eV (yellow color). The differential magnetic susceptibility of 2C7CuBr in the temperature range 80–300 K indicates the effective magnetic moment μeff = 2.05 BM.
关键词： 2D hybrid perovskite,optical properties of halide perovskite,phase transition,magnetic properties of Cu perovskite
更新于2025-09-23 15:23:52
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Optical, magnetic and ferroelectric properties of Ba0.2Cu0.8-xLaxFe2O4 (x?=?0.2–0.6) nanoparticles
摘要： The Ba0.2Cu0.8-xLaxFe2O4 (x = 0.2, 0.4 & 0.6) (BCLF) nanoparticles were prepared by hydrothermal method and further characterized for structural, morphological, optical, magnetic, and ferroelectric properties. The structural analysis was carried out using X-ray diffraction spectra. These results revealed that all the samples showed the presence of cubic spinel phases. The Fourier transform infrared (FTIR) studies expressed the formation of broad (ν1) and narrow (ν2) absorption bands which can reflect the arrangement of cations between tetrahedral (ν1) and octahedral (ν2) sites. The surface morphology was studied using the field emission scanning and transmission electron microscopes (FESEM & TEM). The FESEM pictures expressed the gradual formation of nanofibers with increase of La-content. The variation of optical bandgap (Eg~1.96–2.15 eV) as a function of substituent concentration was elucidated. The magnetization versus applied magnetic field (M–H) loops of BCLF nanoparticles showed the superparamagnetic nature which can be useful for the biomedical applications. The cation distribution was made between the octahedral (B) and tetrahedral (A) sites using the Neel's two-sublattice model.
关键词： Nanoparticles,Structure,Optical properties,Rare Earth,Magnetic properties
更新于2025-09-23 15:23:52
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The first synthesis of CdFe12O19 nanostructures and nanocomposites and considering of magnetic, optical, electrochemical and photocatalytic properties
摘要： CdFe12O19 nanostructures and nanocomposites were synthesized via sol-gel auto-combustion method. The CdFe12O19/CdTiO3 nanocomposites were prepared at 850 ?C after 1 h calcination, when molar ratio of Cd:Ti is 1:1. Effects of the molar ratio of Cd:Ti, type of precursor and calcination temperature were investigated. Both nanostructures and nanocomposites were ferromagnetic at room temperature, with saturation magnetizations (Ms) 2.561 and 11.269 emu g–1, and coercivities (Hc) 696.517 and 969.068 Oe, respectively. SEM, TEM, FTIR, EDS and XRD showed morphology, composition and particle size of the products. VSM, UV-Vis and CV were used to investigate the magnetic, optical and electrochemical properties. The band gap values of the nanocomposites were larger than that in the nanostructures. Also photocatalytic properties of the nanocomposites were investigated. This is the first attempt on the study of photocatalytic performance of the cadmium hexaferrite nanostructures and nanocomposites. The effects of various factors including composition and particle size of the nanocomposites, the Ti:Cd molar ratio and also kind of organic dye on the photocatalytic behavior of the products were evaluated. The photocatalytic activity achieved a maximum when ratio of Ti:Cd was 1:1. Methyl orange, methylene blue and methylene violet decompositions were about 71.35, 55.08 and 62.27% by nanocomposites, respectively.
关键词： Nanostructures,Photocatalytic,Optical properties,Ferrites.,Magnetic properties
更新于2025-09-23 15:23:52
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Fraction of Rare-Earth (Sm/Nd)-Lanthanum Ferrite-Based Perovskite Ferroelectric and Magnetic Nanopowders
摘要： Multiferroic compound, especially LaFeO3-based perovskite nanopowders that exhibit robust simultaneous ferromagnetism and ferroelectricity, are widely investigated and applied in different applications. In this work, we report the synthesis and characterization pertaining to fraction of rare-earth (Sm/Nd)-substituted lanthanum ferrite based perovskite nanopowders via solid-state technique. The multiferroic phenomenon is the fundamental approach to combine both the ferromagnetic and ferroelectric properties in a single system. Reduction in crystallite size, as well as some lattice distortion effects, are included to show the possibilities of tuning the lattice structure, electrical, optical as well as the magnetic properties which are closely connected to the ferroelectric behavior and magnetism. At room temperature, the ferroelectric behavior of La0.9(Sm/Nd)0.1FeO3 exhibiting a P-E hysteresis loop became more and more pronounced, indicating the electrical leakage is greatly reduced. The canted antiferromagnetic hysteresis loop shows that the rare-earth (Sm/Nd) ion can significantly affect the magnetic parameters of the materials.
关键词： Lanthanum ferrite,x-ray diffraction,optical and magnetic properties,solid-state reaction,ferroelectric,UV–Vis spectroscopy
更新于2025-09-23 15:23:52
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Structural, optical and magnetic elucidation of co-doped of Nd+3 and Pr+3 on lithium nanoferrites and its technological application
摘要： LiNiCo spinel ferrites were prepared, by doping with rare earth metals Nd and Pr, according to micro-emulsion method. In order to study the effect of Nd and Pr, the crystal structure and magnetic properties of prepared ferrites were scrutinized in detail. The endorsement of single-phase spinel ferrites with the co-occurrence of orthophase was confirmed by XRD and FTIR. The average crystallite size varied with increasing the doped concentration of Nd and Pr, which is in the range from 28nm to 70nm. Magnetic properties were analyzed by VSM within range of -10000Oe and 10000Oe. MS and MR values decreased with the increase in concentration. The value of HC, MR, and MS showed stability for transformer core where electromagnetic interference is reduced. Hence synthesized ferrites LiNi0.35-yCo0.15PryNdxFe2-xO4 are suitable for transformers and induction.
关键词： Microemulsion,XRD,Li-Pr,Neodymium,Nanocrystalline ferrites,Praseodymium,Magnetic properties
更新于2025-09-23 15:23:52
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Structural, photoluminescence and magnetic properties of Cu-doped SnO2 nanoparticles co-doped with Co
摘要： Co doped Sn0.98Cu0.02O2 nanoparticles have been synthesized by co-precipitation method. The prepared nanoparticles were characterized by X-ray diffraction, scanning electron microscope (SEM), transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence and magnetic measurements. The observed tetragonal rutile structure confirmed by XRD patterns was not altered by Co-doping and the value of average crystallite size lies within 8–14 nm. The formation of high density defect states and the new phases of Co and Sn were responsible for the reduction of energy gap (Eg) with Co-doping; Eg varied between 3.12 and 3.58 eV. The tuning of band gap and luminescence properties by Co-doping suggested that Co = 4% doped sample is a promising material for selective coatings for solar cells; use as antireflective coating materials, and for fabrication of optoelectronic devices. FTIR spectrum has been used to authenticate the formation of Sn–O bond and the existence of Co in Sn–Cu–O. The promotion of higher local disorders and the oxygen-related defects during growth process of SnO2 nanoparticles at Co = 4% is responsible for the higher UV/violet/blue band photoluminescence emission intensity. The overlapping between bound magnetic polarons (BMP) by Co-doping induced the room temperature ferromagnetism. The existence of high density charge carriers and oxygen vacancies at Co = 4% sample might be responsible for highest magnitude of ferromagnetism. The noticed suppression of RTFM at Co = 6% may be due to the enhanced antiferromagnetic interaction between neighbouring Co–Co ion.
关键词： Photoluminescence,SnO2 nanoparticles,XRD,Energy gap,Magnetic properties
更新于2025-09-23 15:23:52