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B. Sosa Coeto

Bio: B. Sosa Coeto is an academic researcher from Universidad Autónoma del Estado de Morelos. The author has contributed to research in topics: Powder mixture & Ceramic. The author has an hindex of 2, co-authored 2 publications receiving 9 citations.

Papers
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TL;DR: In this paper, the phase formation process in the zone of laser irradiation of 60 wt.% Al2O3-40 wt% TiO2 compacts has been investigated by the XRD, electron microscopy and atomic force microscopy methods.
Abstract: The phase formation process in the zone of laser irradiation of 60 wt.% Al2O3–40 wt.% TiO2 and 60 wt.% Al2O3– 40 wt.% Y2O3 compacts has been investigated by the XRD, electron microscopy, and atomic force microscopy methods. In the laser irradiation zone the ceramic track is formed. Due to no uniformity of heating of the powder mixture Al2O3–TiO2 the ceramic track consists of a surface layer of the α-Al2TiO5 and the bulk layer from the βAl2TiO5. Ceramic track formed during irradiation of Al2O3-Y2O3 mixture consists of a surface amorphous layer of Y3Al5O12 with inclusions of α-Al2O3 domains and the bulk layer consisting of a mixture of dendrites α-Al2O3 and Y3Al5O12.

8 citations

Journal ArticleDOI
TL;DR: In this paper, the defect formation and reaction processes in a ZnO+ 1%Gd 2 O 3 powder mixture during its mechanical and laser processing were studied using X-ray diffraction, electron paramagnetic resonance and Fourier transform infrared spectroscopy.
Abstract: X-ray diffraction, electron paramagnetic resonance, Fourier transform infrared spectroscopy and scanning electron microscopy were used to study the defect formation and reaction processes in a ZnO + 1%Gd 2 O 3 powder mixture during its mechanical and laser processing. Mechanical treatment of the ZnO + 1%Gd 2 O 3 powder mixture leads to a grinding of initial ZnO particles and formation of three types of superficial paramagnetic donor defect centers. The rise of the sample temperature with increasing processing time promotes a successive annealing of ZnO defects with small activation energies and of superficial defects in Gd 2 O 3 . The formation of a ZnO:Gd 3+ solid solution in the used mechanical processing regimes has not been observed. Laser surface melting of the ZnO + 1%Gd 2 O 3 pellets provokes formation of a surface layer exhibiting a texture. The crystallization directions in the superficial layers of different specimens have a random character. In the superficial layers and deep sub-surface layers, processes of solid-state interactions (formation of an inhomogeneous ZnO:Gd 3+ solid solution) take place. The surplus charges of the Gd 3+ ions are compensated by the formation of Zn vacancies or interstitial oxygen ions which in the laser-surface-melted layers are located closer to the Gd 3+ ions than in the case of single-crystalline samples.

2 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the synthesis of 0.1% Gadolinium (Gd) doped Zinc oxide (ZnO) nanophosphor by solution combustion method using Oxalyl dihydrazide (ODH) fuel was described.

54 citations

Journal ArticleDOI
TL;DR: In this article, the influence of Ga3+ doping on the dielectric properties of RE3Al5O12 (RE=Tb, Y, Er, Yb) ceramics has been investigated.

25 citations

Journal ArticleDOI
TL;DR: In this paper, the microstructure of the ceramic tracks depends on the ratio of the phases formed in rapid cooling of the eutectic melts, and phase formation proceeded within the framework of Al 2 O 3 -Y 2 O O 3 and Y 2O 3 -TiO 2 binary mixtures.

7 citations

Journal ArticleDOI
TL;DR: The EPR spectrum of Mn 2+ ions observed in nano-powders of wurtzite ZnO phase (ZnO Wt ) with 0.1% of carbon nanoparticles subjected to mechanical processing (MP) for t MP > 90 min where different than the well-known EPR spectra of NM 2+ in Zn O Wt.

5 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of processing parameters on the properties of alumina-titanate nanocomposites has been investigated and a polymer-assisted co-precipitation route has been employed to synthesize nanoparticles.
Abstract: The present investigation reveals the effect of processing parameters on the properties of alumina–titania (Al $$_{2}$$ O $$_{3}$$ –TiO $$_{2}$$ ) nanocomposites. A polymer-assisted (Pluronic P123 triblock co-polymer) co-precipitation route has been employed to synthesize $$\hbox {Al}_{2}\hbox {O}_{3}$$ – $$\hbox {TiO}_{2}$$ nanoparticles. As a surfactant, pluronic P123 polymer exhibits hydrophobic as well as the hydrophilic nature simultaneously which detains the agglomeration and hence the nano size particle have been obtained. Effect of surfactant concentration on morphology and particle size of product has also been investigated. Thermal behaviour of the prepared powder samples have been studied using differential scanning calorimeter/thermal gravimetric analysis and dilatometer. Formation of aluminium-titanate $$(\hbox {Al}_{2}$$ $$\hbox {TiO}_{5})$$ phase has been confirmed using X-ray diffraction analysis. It has been observed by field emission scanning electron microscopy analysis that the particle size reduced effectively (below 100 nm) when polymer-assisted co-precipitation route is used instead of the simple co-precipitation technique. A highly dense microstructure of sintered samples has been obtained, driven by reduced particle size.

4 citations