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Synthesis of ZnS:Tm3+Nanoparticles by the Polyol Method

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Open Journal of Applied Sciences 2019年第7期9卷 613-619页

作者： Francisco Jesus Rodriguez Joan Reyes Dulce Y. Medina miguel angel barron Catalina Haro-Perez Ciencias Básicas e Ingeniería Universidad Autónoma Metropolitana Mexico City México

In this work, the synthesis of undoped and Tm-doped ZnS nanoparticles is successfully carried out by the polyol method. From XRD analyses, it was confirmed that both types of particles possess the cubic zinc blend structure of the ZnS, and that the structure is not altered by doping. The crystallite size computed by the Scherrer equation is about 9 ± 1 nm. From photoluminescence analyses, the results show that the excitation spectrum has two excitation peaks at 304 nm and 356 nm;by exciting at 304 nm, a strong blue emission is observed at 420 nm, while exciting at 356 nm the characteristic Tm transition 1G4 → 3H6 is observed at 417 nm. By doping with Tm ions, the emission color changes from pure blue to sky according to the change in CIE coordinates from x = 0.15, y = 0.015 to x = 0.18, y = 0.17, respectively.

关键词： Luminescence Zinc Sulfide Blue Emission

Numerical and Physical Modeling of Turbulence in a Peirce-Smith Copper Converter

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材料科学与工程（中英文A版） 2013年第7期3卷 510-518页

作者： Aaron Almaraz Cesar Lopez miguel angel barron Meza Gabriel Plascencia Technological Research and Innovation Center 1PN Cerrada CECATI s/n Col. Sta. Catarina Mexico D.F. 02250 Mexico Materials Department Azcapotzalco Metropolitan Autonomous University Av. San Pablo 180 Azcapotzalco D.F. 02200 Mexico

In this work, a numerical and experimental analysis of the very early stages of biphasic flow and the onset of turbulence in Peirce-Smith copper converters with submerged lateral air injection is presented. Dimensions and operating conditions corresponding to industrial size copper converters are employed in 2D transient two-phase numerical simulations. A submergence depth for tuyeres of 0.5 m and 1.0 m of molten bath depth were assumed in the numerical simulations. Air velocities at the nozzle inlet were varied from 5 to 50 m/s, and integration times up to 10 s were considered. A transition from bubbling to jetting regime is observed as injection velocity is increased. Computer results show that the metallostatic pressure exerted by the molten copper pushes the injecting jet towards the nearest converter wall. Results from a set of independent tests conducted in a water model validate the numerical data obtained.

关键词：流动数值模拟转换器史密斯物理模拟湍流铜空气喷射注射速度

Numerical Study of Solid Iron Carburization in a Carbon Monoxide Atmosphere

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材料科学与工程（中英文B版） 2013年第9期3卷 582-585页

作者： miguel angel barron Meza G. Plascencia Aaron Almaraz Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Av. San Pablo 180 Col. Reynosa-TamaulipasMexico D.F. 02200 Mexico CIITEC-IPN Cerrada Cecati s/n Col. Sta. Catarina Mexico D.F. 02250 Mexico

The diffusion step during the high temperature carburization of a spherical iron particle in a carbon monoxide atmosphere is mathematically modeled and numerically simulated in this work. The continuity equation is numerically solved using a forward finite-differences scheme, and a temperature range of 1,486-1,664 K is considered. An integration time during which the solid iron particle is not yet melted is assumed. The programming code was verified using experimental results previously reported by other authors. Radial carbon concentration is determined for several temperatures, and the average carbon concentration in the particle is obtained by numerical integration.

关键词：一氧化碳固体渗碳铁颗粒数值研究气氛温度范围连续性方程数值模拟

Synthesis of Tenoltrifluoroacetone Composite Doped with Terbium, Dysprosium and Europium Encapsulated in Silica Oxide Matrix

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Journal of Surface Engineered Materials and Advanced Technology 2020年第4期10卷 63-74页

作者： Yazmin Francisco Dulce Medina miguel barron Joan Reyes Pedro Adrian Martinez angel de Jesus Morales Elizabeth Garfias Universidad Autónoma Metropolitana Departamento de Materiales Ciencias Básicas e Ingeniería Reynosa Tamaulipas México Instituto Politécnico Nacional ESIQIE UPALM S/N Mexico City México

The synthesis of the thenoyltrifluoroacetone compound doped with terbium, dysprosium and europium encapsulated in a silica matrix (TTA:Tb:Dy:Eu@SiO2) were performed by the sol-gel method. The precursors to obtain the vitreous phase (SiO2) were: Tetraethylorthosilicate (TEOS, C8H2O4Si, 98%, Aldrich), and ethyl alcohol (CH3CH2OH, 99.5%, Meyer), distilled water and 0.05 ml of hydrochloric acid (HCl, Meyer). The sample with molar ratio 20:80 TTA:Tb:Dy:Eu@SiO2 has the best emission intensity. Thermogravimetric analysis (TGA) shown that silica encapsulated samples decompose at lower temperatures than pure TTA:Tb:Dy:Eu luminescent material. Fourier Transform Infrared (IR-TF) shown the characteristic Si-O-Si bands that are presented at a wavelength of 1049, 853 and 440 cmǃ confirming that the luminescent material is encapsulated in a silica matrix, finally X-ray diffraction (XRD) shown that TTA:Tb:Dy:Eu@SiO2 composite is amorphous.

关键词： Synthesis Luminescence Composite Sol-Gel Terbium Dysprosium and Europium

Red, White and Blue Light Emission from Europium Doped Al2O3 Confined into a Silica Matrix

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Open Journal of Applied Sciences 2018年第8期8卷 338-345页

作者： Joan Reyes Dulce Y. Medina Miriam Aguilar miguel A. barron Elizabeth Garfias angel de Jesus Morales Ciencias Básicas e Ingeniería Universidad Autónoma Metropolitana-Azcapotzalco Reynosa México Instituto Politécnico Nacional ESIQIE Mexico City México

The main drawbacks of fluorescent activated lanthanide luminescent materials in practical optoelectronic applications are the high cost of raw material and the limitation of a specific color depending on the lanthanide ion. In this work, the synthesis of red, white and blue light emitting composite powders of Al2O3:Eu3+@SiO2 were successfully synthesized by the hydrolysis and condensation reactions of TEOS as the raw precursor of silica matrix on the Al2O3:Eu3+ surface. With the aim to change the CIE coordinates different weight ratios of Al2O3:Eu3+/SiO2 powders from 13Al/87Si to 5Al/95Si were prepared. Besides, various excitation wavelength from 280 to 340 nm was used in order to change the ratio intensity;Ired/Iblue, between the red emission coming from the 5D0→7F2 transition of Eu3+ ions and the blue band of silica matrix. Chemical evolution of the hydrolysis and condensation reaction of TEOS were conducted by FTIR spectroscopy. The results indicate that from 500°C a complete TEOS to SiO2 transformation is carried out.

关键词： Luminescent Lanthanide Luminescence White Emission Aluminium Oxide

Mathematical Modelling of Einstein’s Rate Equations for Zinc Phosphate Glass with Er3+-Yb3+

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Open Journal of Applied Sciences 2021年第9期11卷 1038-1045页

作者： Frida Lissete Flores Rivera Grethell Georgina Pérez-Sánchez miguel angel barron-Meza Joan Reyes Miranda Dulce Yolotzin Medina Velázquez Division of Basic Science and Engineering Universidad Autónoma Metropolitana México City México

There is a constant growth in the demand of data information transmission capacity, that is, more and more people send data, voice, video signals, among others, through communications networks. Due to the above there is great interest in improving network devices, such as optical amplifiers, which must cover a large bandwidth and generate greater gain than those currently available. For this reason in this work a computational simulation for a Quasi-system was carried out three energy levels of Erbium and Ytterbium varying their concentrations and proving that they are optimal candidates in a zinc phosphate matrix as this type of glass contains properties such as, high transparency, low melting point, high thermal stability, high gain density due to high solubility, low refractive index and low dispersion, which makes them optimal as signal amplifiers. The results confirm that by increasing the doping of the Erbium ion the gain of the amplifier decreases, contrary to the Ytterbium ion that by increasing the doping the gain of the amplifier increases.

关键词： Optical Telecommunications Rare Earths Doping Optical Amplifier Gain

Luminescent Properties of the Mn2+Ion in Zinc Phosphate Glass

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Open Journal of Applied Sciences 2021年第11期11卷 1212-1217页

作者： Frida Lissete Flores Rivera Dulce Yolotzin Medina Velazquez Gabriela Verenice Arredondo Martínez Jorge Roberto Oliva Uc Carlos Eduardo Rodriguez Garcia miguel angel barron-Meza Joan Reyes Miranda Autonomus Metropolitan University Material Area Mexico City Mexico Potosino Institute for Scientific and Technological Research Advanced Materials Division San Luis Mexico Faculty of Physics-Mathematics Autonomous University of Coahuila Saltillo Mexico

In the development of new optoelectronic devices, mainly those related to solid state technology (SSL), the generation of luminescent materials with high intensity in visible region and low cost is of vital importance. For this reason, this work presents the luminescent properties of zinc phosphate glasses doped with the manganese ion 2+. The manganese ion offers a series of advantages with respect to rare earths, such as a more accessible cost and an intense emission in the red color that make it a great candidate for the generation of new optoelectronic devices. The methodology for the synthesis is presented in this work, as well as its luminescent properties, for concentrations of 2%, 10%, 13% and 15% atomic.

关键词： Luminescence Manganese Advanced Glasses