N.B. Ibrahim

The physical properties of erbium-doped yttrium iron garnet films prepared by sol-gel method

ErxY3-xFe5O12 nanoparticle films (x = 0.0, 0.6, 1.2, 2.0, and 2.5) have been synthesized by a sol-gel technique. All of the samples were annealed at 1000°C. The nanostructures were characterized by an X-ray diffractometer (XRD), the magnetic properties and the grain size were studied using a vibrating sample magnetometer (VSM), and a field emission scanning electron microscope (FE-SEM), respectively. The XRD patterns of the films show single phase structure. The sizes of the particles are in the range of 78 to 89 nm. The VSM result shows that the saturation magnetization of ErxY3-xFe5O12 films decreased with the increment of Er concentration (x).

Effects of Annealing Temperature on Structure and Magnetic Properties ofTbxY3−xFe5O12(x=0.2and 0.4) Thin Films

Terbium-substituted yttrium iron garnet (TbxY3-xFe5O12 (x = 0.2 and 0.4)) thin films have been successfully prepared by a sol-gel method followed by spin-coating process. The annealing of the films was performed at different temperatures like 700, 800, and 900°C and found that the films annealed at 900°C turned out to be crystallized into a pure garnet phase. All of the films were bearing grains of nanometer in size. Increasing the annealing temperature gave extra energy to the grains causing to be agglomerates. The lattice contraction occurred as the grains sizes were decreased due to the decrease of Fe2+ formation. The magnetic measurements show that all of the films are soft magnetic materials with low saturation magnetization values. The hysteresis loops of the films which were annealed at 900°C were found angular in shape similar to the single crystal-like YIG film.

Characterization of Erbium Substituted Yttrium Iron Garnet Films Prepared by Sol-Gel Method

Yttrium iron garnet (YIG) thin films substituted erbium ions (Er+3) Er0.4Y2.6Fe5O12 films were prepared by a sol-gel method at different temperatures which varied from 800 to 1000°C for 2 hours in air. Magnetic and microstructural properties of the films were characterized with X-ray diffraction (XRD), the field emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM). The XRD patterns of the sample have only peaks of the garnet structure. The lattice constants decrease, while the particle size increases from 51 to 85 nm as the annealing temperature increases with average in thickness of 300 nm. The saturation magnetization and the coercivity of the samples increased from 26 (emu/cc) and 28 Oe for the film annealed at 800°C to 76 (emu/cc) and 45 Oe for film annealed at 1000°C, respectively.

Morphological Distinctions on CdSe QDs Synthesized via Auto Clave and Organometallic Route

Quantum dots (QDs) semiconductors exhibit size-dependent Opto-electronic properties and customizable bandgaps that can be engineered to match the solar spectrum [. Organometallic synthetic approach relies on the injection of organometallic precursor into a pyrolyphic mixture at elevated temperature sufficient enough to initiate particle growth. This approach entails precise control of temperature gradient [. Organometallic reagents injected into a heated non-coordinating octadecene (ODE) were compatible with oleic acid (OA) that was used to protect the CdSe QDs against oxidation and emission loss. ODE is stable in air and has a low melting point (below 20 oC) making it easier to be handled at room temperature. Its high boiling point (about 360 oC) coupled with its inert nature, less toxicity, low cost and good dissolving power makes it an ideal solvent for the growth of CdSe QDs [3,4,5 and 6]. However, QDs synthetic methods differ and relies on how the thermodynamic properties of the reactant mixtures are varied. QDs nucleation growth depicted the underlying processes occurring in aqueous solution and the need to control thermodynamic variables such as reaction time and temperature of the reactants as well as non-thermodynamic variable such as stirring speeds.

Effects of annealing temperature on structure and magnetic properties of Tb x Y 3-x Fe 5 O 12 ( x = 0.2 and 0.4) thin films

Terbium-substituted yttrium iron garnet (TbxY3-xFe5O12 (x = 0.2 and 0.4)) thin films have been successfully prepared by a sol-gel method followed by spin-coating process. The annealing of the films was performed at different temperatures like 700, 800, and 900°C and found that the films annealed at 900°C turned out to be crystallized into a pure garnet phase. All of the films were bearing grains of nanometer in size. Increasing the annealing temperature gave extra energy to the grains causing to be agglomerates. The lattice contraction occurred as the grains sizes were decreased due to the decrease of Fe2+ formation. The magnetic measurements show that all of the films are soft magnetic materials with low saturation magnetization values. The hysteresis loops of the films which were annealed at 900°C were found angular in shape similar to the single crystal-like YIG film.

Structure and Magnetic Properties of Fe5O12 (, and 2.0) Thin Films Prepared by Sol-Gel Method

Nanoparticles Fe5O12 (, 1.0, and 2.0) thin films were prepared by sol-gel method and treated at 800, 900, and 1000∘C, respectively, for 2 h. The films have single phase garnet structure and the sizes of particles are in the range of 44 to 83 nm. The magnetic measurements show that the saturation magnetization decreased with increasing of Er concentration for all samples treated at different annealing temperatures. The saturation magnetization increased with the particle size due to the enhancement of the surface spin effect. The coercivity initially decreased for and then increased for with increasing annealing temperature.

Influence of erbium on the structural, optical and magnetic properties of sol–gel Ce: YIG films

AbstractSol–gel Y2.8-xCe0.2ErxFe5O12 (x = 0.0, 0.2, 0. 4, 0.6, 0.8 and 1.0) nanofilms were successfully prepared for their potential use in nonreciprocal magneto-optical devices, such as isolators and circulators. The effect of Er-doped Ce-substituted yttrium iron garnet (Ce:YIG) was investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), UV–vis spectrophotometry and vibrating sample magnetometry (VSM). Analysis of the diffractograms indicated a cubic garnet structure and the incorporation of the Er3+ ions into the Ce: YIG. The absorption bands in IR spectra revealed the fingerprint of the YIG structure in the obtained films. The optical transparency of the Er-doped Ce:YIG samples was above 98% in the visible and near infrared region wavelengths. All samples were soft ferrimagnetic films, as indicated by their hysteresis loops and low magnetic coercivity fields (~50 Oe). As more erbium ions were introduced, the saturation magnetisation decreased and the magnetic coercivity increased. These findings suggest that Er-doped Ce:YIG films may have a promising role in magneto-optical applications.

Structural, optical and magnetic properties of Er3+, Tb3+: YIG films prepared by sol-gel method

Nanoparticle Y2.8-xTb0.2ErxFe5O12 (x = 0, 0.8, 1.4, 1.8, and 2.2) films were successfully prepared using a sol-gel method. The films were deposited on a quartz substrate, followed by annealing process in air at 900 °C. The XRD patterns revealed the single-phase garnet structure of obtaining films. The results confirmed the successful incorporation of erbium and terbium ions into the YIG structure. The lattice parameter increases at low Er3+ concentration, then decreases with increment of Er3+ ions and the lowest value of 12.34 A was obtained at (x = 2.2). The sizes of nanoparticles are in the average range from 29 to 46 nm. The addition of Er3+ ions significantly enhanced the transparency (from 64 % to 95 %) in the visible and near infrared region. Magnetic properties study showed that all films are soft ferrimagnetic materials. The saturation magnetization value increased to 190 emu/cm3 at (x=1.4), then decreased dramatically with increment of x content. Coercivity field noticeably increased with the increments of x content.Nanoparticle Y2.8-xTb0.2ErxFe5O12 (x = 0, 0.8, 1.4, 1.8, and 2.2) films were successfully prepared using a sol-gel method. The films were deposited on a quartz substrate, followed by annealing process in air at 900 °C. The XRD patterns revealed the single-phase garnet structure of obtaining films. The results confirmed the successful incorporation of erbium and terbium ions into the YIG structure. The lattice parameter increases at low Er3+ concentration, then decreases with increment of Er3+ ions and the lowest value of 12.34 A was obtained at (x = 2.2). The sizes of nanoparticles are in the average range from 29 to 46 nm. The addition of Er3+ ions significantly enhanced the transparency (from 64 % to 95 %) in the visible and near infrared region. Magnetic properties study showed that all films are soft ferrimagnetic materials. The saturation magnetization value increased to 190 emu/cm3 at (x=1.4), then decreased dramatically with increment of x content. Coercivity field noticeably increased with the inc...

Effect of Annealing Temperature on the Structural and Magnetic Properties of Terbium Iron Garnet Thin Films Prepared by Sol-Gel Method

The terbium iron garnet (TbIG) nanoparticle thin films have been prepared by a sol-gel method for potential use as a magnetic sensor. The films were deposited onto clean quartz substrate using a spin coating technique, followed by annealing at different temperature of 700, 800, 900 °C in air for 2 h. As prepare film has been also executed. Microstructural and magnetic properties of the films were measured using an X-ray diffraction (XRD), a Field Emission Scanning Electron Microscope and a Vibrating Sample Magnetometer. The XRD results revealed that the pure phase of garnet structure has been formed at 900 °C. The lattice parameter decreased initially from 11.6 to 11.4 A when annealing temperature increased from 700 to 800 °C, and then it is increased to 12.36 A when annealing temperature increased to 900 °C. The grain sizes increased from 12 to 18 nm with increasing of annealing temperature from 700 to 900 °C, while the thickness of the films decreased to the smallest value of 312 nm at 900 °C. The saturation magnetization increased with increasing of annealing temperature due to increasing of grain sizes. The coercivity of films exhibited a highest value of 102 kA/m at 900 °C.

Effects of Annealing Temperature on Structure and Magnetic Properties of TbY3−Fe5O12 (=0.2 and 0.4) Thin Films

Terbium-substituted yttrium iron garnet (TbxY3-xFe5O12 (x = 0.2 and 0.4)) thin films have been successfully prepared by a sol-gel method followed by spin-coating process. The annealing of the films was performed at different temperatures like 700, 800, and 900°C and found that the films annealed at 900°C turned out to be crystallized into a pure garnet phase. All of the films were bearing grains of nanometer in size. Increasing the annealing temperature gave extra energy to the grains causing to be agglomerates. The lattice contraction occurred as the grains sizes were decreased due to the decrease of Fe2+ formation. The magnetic measurements show that all of the films are soft magnetic materials with low saturation magnetization values. The hysteresis loops of the films which were annealed at 900°C were found angular in shape similar to the single crystal-like YIG film.