2018 |
Meneses-Franco, A; Campos-Vallette, M; Vasquez, S O; Soto-Bustamante, E A Er-Doped Nanostructured Batio3 for Nir to Visible Upconversion Artículo de revista Materials, 11 (10), 2018, ISSN: 1996-1944. Resumen | Enlaces | BibTeX | Etiquetas: barium crystal, dielectric-properties, erbium, fabrication, ions microstructure, nanoparticle, nanoparticles, nanotechnology, particles, photoluminescent, spectra, technology, titanate, upconversion @article{RN409, title = {Er-Doped Nanostructured Batio3 for Nir to Visible Upconversion}, author = { A. Meneses-Franco and M. Campos-Vallette and S.O. Vasquez and E.A. Soto-Bustamante}, url = {/brokenurl#<Go to ISI>://WOS:000448658400164}, doi = {10.3390/ma11101950}, issn = {1996-1944}, year = {2018}, date = {2018-01-01}, journal = {Materials}, volume = {11}, number = {10}, abstract = {Photoluminescent mechanisms in erbium-doped barium titanate nanoparticle systems were studied. Er3+ ions were introduced into the BaTiO3 lattice by the sol-gel method. The resulting Er3+ concentration was between 0% and 5%, with Ba/Ti ratios of 1.008 and 0.993. The stoichiometry of Ba and Ti concentrations in the lattice influenced the doping mechanism and placement of erbium ions in the lattice structure. Our research shows the existence of a strong correlation between Ba/Ti ratios, erbium concentration, phase structure and doping site location on the upconversion photoluminescence mechanisms. Competing upconversion emissions H-2(11/2)/(S3/2I15/2)-S-4-I-4 at 523 and 548 nm respectively and other photoluminescent mechanisms as (I9/2I11/2)-I-4-I-4 around 4000 nm (2500 cm(-1)) were studied using Raman and emission spectroscopy. The upconversion process is predominant over other photoluminescent decay when the material presents high distortion in the surrounding activator.}, keywords = {barium crystal, dielectric-properties, erbium, fabrication, ions microstructure, nanoparticle, nanoparticles, nanotechnology, particles, photoluminescent, spectra, technology, titanate, upconversion}, pubstate = {published}, tppubtype = {article} } Photoluminescent mechanisms in erbium-doped barium titanate nanoparticle systems were studied. Er3+ ions were introduced into the BaTiO3 lattice by the sol-gel method. The resulting Er3+ concentration was between 0% and 5%, with Ba/Ti ratios of 1.008 and 0.993. The stoichiometry of Ba and Ti concentrations in the lattice influenced the doping mechanism and placement of erbium ions in the lattice structure. Our research shows the existence of a strong correlation between Ba/Ti ratios, erbium concentration, phase structure and doping site location on the upconversion photoluminescence mechanisms. Competing upconversion emissions H-2(11/2)/(S3/2I15/2)-S-4-I-4 at 523 and 548 nm respectively and other photoluminescent mechanisms as (I9/2I11/2)-I-4-I-4 around 4000 nm (2500 cm(-1)) were studied using Raman and emission spectroscopy. The upconversion process is predominant over other photoluminescent decay when the material presents high distortion in the surrounding activator. |
2013 |
Campos, C; Munoz, M; Barrientos-Poblete, L; Lang, E; Jara, P; Sobrados, I; Yutronic, N Adhesion of Gold and Silver Nanoparticles onto Urea-Alkylamine Inclusion Compounds Artículo de revista Journal of Inclusion Phenomena and Macrocyclic Chemistry, 75 (1-2), pp. 165-173, 2013, ISSN: 1388-3127. Resumen | Enlaces | BibTeX | Etiquetas: alpha-cyclodextrin, amine aspects, compounds, dynamics gold guests, inclusion molecules, nanoparticle, nanoparticles, reduction, silver structural temperature, thiourea, urea x-ray-diffraction @article{RN137, title = {Adhesion of Gold and Silver Nanoparticles onto Urea-Alkylamine Inclusion Compounds}, author = { C. Campos and M. Munoz and L. Barrientos-Poblete and E. Lang and P. Jara and I. Sobrados and N. Yutronic}, url = {/brokenurl#<Go to ISI>://WOS:000314898300018}, doi = {10.1007/s10847-012-0157-1}, issn = {1388-3127}, year = {2013}, date = {2013-01-01}, journal = {Journal of Inclusion Phenomena and Macrocyclic Chemistry}, volume = {75}, number = {1-2}, pages = {165-173}, abstract = {We report the synthesis and characterization of a new series of urea inclusion compounds containing primary alkylamine (octyl, decyl and dodecyl) as guests, as well as the deposition of gold and silver nanoparticles onto the crystalline surface of these complexes. X-ray diffraction confirms the inclusion process of the amine in the urea cavities. The structures determined for the three complexes correspond to a hexagonal channel structure with space group P6(1)22. Alkylamine-urea stoichiometric ratios in all cases satisfy the relationship 1:3n (n = 2 for octylamine and 3 for decylamine and dodecylamine), determined by elemental analysis. The deposition of gold and silver nanoparticles by the magnetron sputtering technique onto microcrystals of the complexes was analyzed by Diffuse Reflectance Spectroscopy, showing characteristic surface plasmon resonance for metal nanoparticles. Transmission electron microscopy demonstrates the presence of metal nanoparticles (MNPs) in a size range between 5 and 60 nm for gold and between 5 and 20 nm for silver, and furthermore, in some cases it shows vestiges of a hexagonal arrangement of the MNPs. X-ray diffraction and IR measurements demonstrate that the basic structure of the matrix remains unchanged after the MNPs adhesion. IR also shows increased broadening and intensity of the characteristic NH2 bending frequencies (1,597 cm(-1)) when the MNPs interact with the inclusion compounds. We conclude that the interactions between the inclusion compounds and metal nanoparticles occurs mainly through the amino groups of the guest molecules that can emerge from the entrance of the inclusion compound cavities attracted by the metallic nanoparticles, in opposition to the restoring van der Waals interactions present inside channels, which increase with increasing chain length of the guest molecules., Schematic representation of urea inclusion compounds containing primary alkylamine (octyl, decyl and dodecyl) as guests and the deposition of gold and silver nanoparticles onto the crystalline surface of these complexes.}, keywords = {alpha-cyclodextrin, amine aspects, compounds, dynamics gold guests, inclusion molecules, nanoparticle, nanoparticles, reduction, silver structural temperature, thiourea, urea x-ray-diffraction}, pubstate = {published}, tppubtype = {article} } We report the synthesis and characterization of a new series of urea inclusion compounds containing primary alkylamine (octyl, decyl and dodecyl) as guests, as well as the deposition of gold and silver nanoparticles onto the crystalline surface of these complexes. X-ray diffraction confirms the inclusion process of the amine in the urea cavities. The structures determined for the three complexes correspond to a hexagonal channel structure with space group P6(1)22. Alkylamine-urea stoichiometric ratios in all cases satisfy the relationship 1:3n (n = 2 for octylamine and 3 for decylamine and dodecylamine), determined by elemental analysis. The deposition of gold and silver nanoparticles by the magnetron sputtering technique onto microcrystals of the complexes was analyzed by Diffuse Reflectance Spectroscopy, showing characteristic surface plasmon resonance for metal nanoparticles. Transmission electron microscopy demonstrates the presence of metal nanoparticles (MNPs) in a size range between 5 and 60 nm for gold and between 5 and 20 nm for silver, and furthermore, in some cases it shows vestiges of a hexagonal arrangement of the MNPs. X-ray diffraction and IR measurements demonstrate that the basic structure of the matrix remains unchanged after the MNPs adhesion. IR also shows increased broadening and intensity of the characteristic NH2 bending frequencies (1,597 cm(-1)) when the MNPs interact with the inclusion compounds. We conclude that the interactions between the inclusion compounds and metal nanoparticles occurs mainly through the amino groups of the guest molecules that can emerge from the entrance of the inclusion compound cavities attracted by the metallic nanoparticles, in opposition to the restoring van der Waals interactions present inside channels, which increase with increasing chain length of the guest molecules., Schematic representation of urea inclusion compounds containing primary alkylamine (octyl, decyl and dodecyl) as guests and the deposition of gold and silver nanoparticles onto the crystalline surface of these complexes. |
2018 |
Er-Doped Nanostructured Batio3 for Nir to Visible Upconversion Artículo de revista Materials, 11 (10), 2018, ISSN: 1996-1944. |
2013 |
Adhesion of Gold and Silver Nanoparticles onto Urea-Alkylamine Inclusion Compounds Artículo de revista Journal of Inclusion Phenomena and Macrocyclic Chemistry, 75 (1-2), pp. 165-173, 2013, ISSN: 1388-3127. |