2018 |
Diaz, C; Carrillo, D; Campa, De La R; Soto, A P; Valenzuela, M L Solid-State Synthesis of Lnocl/Ln(2)O(3) (Ln = Eu, Nd) by Using Chitosan and Ps-Co-P4vp as Polymeric Supports Artículo de revista Journal of Rare Earths, 36 (12), pp. 1326-1332, 2018, ISSN: 1002-0721. Resumen | Enlaces | BibTeX | Etiquetas: earths, euocl/eu2o3, lanthanide, lanthanides, luminescence, method, nanocrystals, ndocl, oxides, rare scale solventless supracrystals @article{RN397, title = {Solid-State Synthesis of Lnocl/Ln(2)O(3) (Ln = Eu, Nd) by Using Chitosan and Ps-Co-P4vp as Polymeric Supports}, author = { C. Diaz and D. Carrillo and R. De La Campa and A.P. Soto and M.L. Valenzuela}, url = {/brokenurl#<Go to ISI>://WOS:000451031200013}, doi = {10.1016/j.jre.2018.03.031}, issn = {1002-0721}, year = {2018}, date = {2018-01-01}, journal = {Journal of Rare Earths}, volume = {36}, number = {12}, pages = {1326-1332}, publisher = {2018 Chinese Society of Rare Earths. Published by Elsevier B.V.}, abstract = {A series of lanthanide materials of type LnOCl or Ln(2)O(3) (Ln = Eu, Nd) were successfully prepared via a convenient and straightforward two-step procedure. Firstly, and by using chitosan and PS-co-P4VP as polymeric supports, macromolecular complexes of type chitosan LnCl(3) and PS-co-P4VP center dot LnCl(3) were prepared. These macromolecular complexes were treated in solid state at 800 degrees C under air, leading to the corresponding LnOCl or Ln(2)O(3) materials (Ln = Eu, Nd) with moderate to good yields. The nature of the as-prepared lanthanide materials (LnCl and/or Ln(2)O(3)) is strongly influenced by the polymeric template (i.e., chitosan or PS-co-P4VP), the lanthanide salt precursor, and the polymer/lanthanide molar ratio. Thus, when chitosan center dot LnCl(3) and PS-co-P4VP center dot EuCl3 are used as macromolecular precursors, a mixture of crystalline phases o f both EuOCl and Eu2O3 are obtained. However, when chitosan center dot NdCl3 and PS-co-P4VP center dot NdCl3 are used, a sole pure crystalline phase of NdOCl is obtained. The nanostructured lanthanide materials were characterized by means of XRD (X-ray diffraction of powder), SEM, EDS, TEM, and HRTEM. The luminescent spectra of the as-prepared EuOCl/Eu2O3 mixture materials show an emission pattern whose intensity is strongly influenced by the nature of the polymeric precursor, as well as on the metal/polymer molar ratios.}, keywords = {earths, euocl/eu2o3, lanthanide, lanthanides, luminescence, method, nanocrystals, ndocl, oxides, rare scale solventless supracrystals}, pubstate = {published}, tppubtype = {article} } A series of lanthanide materials of type LnOCl or Ln(2)O(3) (Ln = Eu, Nd) were successfully prepared via a convenient and straightforward two-step procedure. Firstly, and by using chitosan and PS-co-P4VP as polymeric supports, macromolecular complexes of type chitosan LnCl(3) and PS-co-P4VP center dot LnCl(3) were prepared. These macromolecular complexes were treated in solid state at 800 degrees C under air, leading to the corresponding LnOCl or Ln(2)O(3) materials (Ln = Eu, Nd) with moderate to good yields. The nature of the as-prepared lanthanide materials (LnCl and/or Ln(2)O(3)) is strongly influenced by the polymeric template (i.e., chitosan or PS-co-P4VP), the lanthanide salt precursor, and the polymer/lanthanide molar ratio. Thus, when chitosan center dot LnCl(3) and PS-co-P4VP center dot EuCl3 are used as macromolecular precursors, a mixture of crystalline phases o f both EuOCl and Eu2O3 are obtained. However, when chitosan center dot NdCl3 and PS-co-P4VP center dot NdCl3 are used, a sole pure crystalline phase of NdOCl is obtained. The nanostructured lanthanide materials were characterized by means of XRD (X-ray diffraction of powder), SEM, EDS, TEM, and HRTEM. The luminescent spectra of the as-prepared EuOCl/Eu2O3 mixture materials show an emission pattern whose intensity is strongly influenced by the nature of the polymeric precursor, as well as on the metal/polymer molar ratios. |
2017 |
Serrano, A; Arana, A; Galdámez, A; Dutt, A; Monroy, B M; Guell, F; Santana, G Effect of the Seed Layer on the Growth and Orientation of the Zno Nanowires: Consequence on Structural Optical Properties Artículo de revista Vacuum, 146 , pp. 509-516, 2017, ISSN: 0042-207x. Resumen | Enlaces | BibTeX | Etiquetas: fabrication, layer, luminescence, nanostructures, networks, photoluminescence pressure properties, pyrolysis, seed spray sputtering, temperature, thin-films, ultrasonic zinc-oxide zno @article{RN363, title = {Effect of the Seed Layer on the Growth and Orientation of the Zno Nanowires: Consequence on Structural Optical Properties}, author = { A. Serrano and A. Arana and A. Gald\'{a}mez and A. Dutt and B.M. Monroy and F. Guell and G. Santana}, url = {/brokenurl#<Go to ISI>://WOS:000416184600065}, doi = {10.1016/j.vacuum.2017.03.010}, issn = {0042-207x}, year = {2017}, date = {2017-01-01}, journal = {Vacuum}, volume = {146}, pages = {509-516}, publisher = {2017 Elsevier Ltd.}, abstract = {High quality vertically aligned zinc oxide (ZnO) nanowires (NWs) were grown on Au-coated aluminum doped zinc oxide (AZO) thin films via vapor-liquid-solid (VLS) technique. AZO seed layers were deposited using two different techniques named as ultrasonic spray pyrolysis (USP) and magnetron sputtering. Structural, morphological and compositional properties of the NWs grown on the two distinct seed layers were analyzed in detail by using X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques, respectively. In the first case, (seed layer grown by USP technology), NWs showed the (101) orientation, whereas in the second case, (seed layer grown by sputtering) NWs showed (002) orientation. It was confirmed by the SEM images, that NWs with (002) orientation shown better vertical alignment than NWs with (101) orientation. In addition, optical properties were also studied using photoluminescence (PL) spectroscopy and irrespective of the preferred orientation, NWs showed a strong green emission at room temperature. The study made in the present work on the seed layer preparation by two techniques and hence, deposition conditions to achieve fully controllable ZnO nanowires with precise distance, shape, position and orientation could provide opportunities for the fabrication of future optoelectronic devices.}, keywords = {fabrication, layer, luminescence, nanostructures, networks, photoluminescence pressure properties, pyrolysis, seed spray sputtering, temperature, thin-films, ultrasonic zinc-oxide zno}, pubstate = {published}, tppubtype = {article} } High quality vertically aligned zinc oxide (ZnO) nanowires (NWs) were grown on Au-coated aluminum doped zinc oxide (AZO) thin films via vapor-liquid-solid (VLS) technique. AZO seed layers were deposited using two different techniques named as ultrasonic spray pyrolysis (USP) and magnetron sputtering. Structural, morphological and compositional properties of the NWs grown on the two distinct seed layers were analyzed in detail by using X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques, respectively. In the first case, (seed layer grown by USP technology), NWs showed the (101) orientation, whereas in the second case, (seed layer grown by sputtering) NWs showed (002) orientation. It was confirmed by the SEM images, that NWs with (002) orientation shown better vertical alignment than NWs with (101) orientation. In addition, optical properties were also studied using photoluminescence (PL) spectroscopy and irrespective of the preferred orientation, NWs showed a strong green emission at room temperature. The study made in the present work on the seed layer preparation by two techniques and hence, deposition conditions to achieve fully controllable ZnO nanowires with precise distance, shape, position and orientation could provide opportunities for the fabrication of future optoelectronic devices. |
2011 |
Osorio-Roman, I O; Ortega-Vasquez, V; Vargas, V; Aroca, R F Surface-Enhanced Spectra on D-Gluconic Acid Coated Silver Nanoparticles Artículo de revista Applied Spectroscopy, 65 (8), pp. 838-843, 2011, ISSN: 0003-7028. Resumen | Enlaces | BibTeX | Etiquetas: coated d-gluconic emission, enhanced film fluorescence, luminescence, nanoparticles, nanopartides, plasmon raman resonance scattering, see, serrs, silver surface-enhanced @article{RN48, title = {Surface-Enhanced Spectra on D-Gluconic Acid Coated Silver Nanoparticles}, author = { I.O. Osorio-Roman and V. Ortega-Vasquez and V. Vargas and R.F. Aroca}, url = {/brokenurl#<Go to ISI>://WOS:000293206800002}, doi = {10.1366/11-06279}, issn = {0003-7028}, year = {2011}, date = {2011-01-01}, journal = {Applied Spectroscopy}, volume = {65}, number = {8}, pages = {838-843}, abstract = {Coated silver (Ag) colloids synthesized with D-glucose permit the observation of surface-enhanced fluorescence (SEF) and surface-enhanced resonance Raman scattering (SERRS) of the rhodamine B (RhB) molecule. The organic coating formed during the synthesis of the Ag nanostructures was identified by its surface-enhanced Raman scattering (SERS) spectrum as D-gluconic acid. The RhB molecule is used to exemplify the distance dependence of SEF and SERRS on the coated Ag nanostructures. The fluorescence enhancement factor for RhB on D-gluconic acid coated silver nanoparticles was determined experimentally and estimated using a simple model. Further support for the plasmon enhancement is obtained from the fact that the measured fluorescence lifetime of RhB on the silver coated with D-gluconic acid is shorter than that found on a glass surface. A very modest enhancement factor is obtained, as expected for very short distance between RhB and the metal surface. Given the very thin metal fluorophore separation, estimated from the size of the D-gluconic acid, the energy transfer or fluorescence quenching is still efficient and the SEF enhancement is just overcoming the energy transfer. Therefore, both SEF and SERRS are observed. Notably, the aggregation of coated nanoparticles also increases the enhancement factor for SEF.}, keywords = {coated d-gluconic emission, enhanced film fluorescence, luminescence, nanoparticles, nanopartides, plasmon raman resonance scattering, see, serrs, silver surface-enhanced}, pubstate = {published}, tppubtype = {article} } Coated silver (Ag) colloids synthesized with D-glucose permit the observation of surface-enhanced fluorescence (SEF) and surface-enhanced resonance Raman scattering (SERRS) of the rhodamine B (RhB) molecule. The organic coating formed during the synthesis of the Ag nanostructures was identified by its surface-enhanced Raman scattering (SERS) spectrum as D-gluconic acid. The RhB molecule is used to exemplify the distance dependence of SEF and SERRS on the coated Ag nanostructures. The fluorescence enhancement factor for RhB on D-gluconic acid coated silver nanoparticles was determined experimentally and estimated using a simple model. Further support for the plasmon enhancement is obtained from the fact that the measured fluorescence lifetime of RhB on the silver coated with D-gluconic acid is shorter than that found on a glass surface. A very modest enhancement factor is obtained, as expected for very short distance between RhB and the metal surface. Given the very thin metal fluorophore separation, estimated from the size of the D-gluconic acid, the energy transfer or fluorescence quenching is still efficient and the SEF enhancement is just overcoming the energy transfer. Therefore, both SEF and SERRS are observed. Notably, the aggregation of coated nanoparticles also increases the enhancement factor for SEF. |
2018 |
Solid-State Synthesis of Lnocl/Ln(2)O(3) (Ln = Eu, Nd) by Using Chitosan and Ps-Co-P4vp as Polymeric Supports Artículo de revista Journal of Rare Earths, 36 (12), pp. 1326-1332, 2018, ISSN: 1002-0721. |
2017 |
Effect of the Seed Layer on the Growth and Orientation of the Zno Nanowires: Consequence on Structural Optical Properties Artículo de revista Vacuum, 146 , pp. 509-516, 2017, ISSN: 0042-207x. |
2011 |
Surface-Enhanced Spectra on D-Gluconic Acid Coated Silver Nanoparticles Artículo de revista Applied Spectroscopy, 65 (8), pp. 838-843, 2011, ISSN: 0003-7028. |