Analysis of the upconversion emission of yttrium orthoaluminate nanoperovskite co-doped with Er3+/Yb3+ ions for thermal sensing applications

[EN] The upconversion emissions of yttrium orthoaluminate nano-perovskite co-doped with Er3+/Yb3+ have been studied. Strong green and red upconversion emissions, which can be observed by naked eyes, were observed when exciting the sample at 980 nm. In particular, the green band was monitored as a function of temperature and the obtained results suggest that this nano-perovskite can be used as an optical temperature sensor by exciting in the infrared range. The viability of YAP: Er3+/Yb3+ nano-perovskite in laser heating applications has been tested and discussed.This research was partially supported MINECO (MAT2013-46649-C4-2/4-P, MAT2015-71070-REDC, and MAT2016-75586-C4-2/4-P), and by the EU-FEDER. M.A. Hernández-Rodríguez thanks to MINECO for FPI grant (BES-2014-068666).Hernández-Rodríguez, M.; Lozano-Gorrín, A.; Lavin, V.; Rodriguez-Mendoza, U.; Martin, I.; Manjón, F. (2018). Analysis of the upconversion emission of yttrium orthoaluminate nanoperovskite co-doped with Er3+/Yb3+ ions for thermal sensing applications. Journal of Luminescence. 202:316-321. https://doi.org/10.1016/j.jlumin.2018.05.078S31632120

Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.html."[EN] The structural and vibrational properties of nanocrystalline yttrium orthoaluminate perovskite (YAlO3) under compression have been experimentally studied. Experimental results have been compared to ab initio simulations of. bulk YAlO3, in the framework of the density functional theory. Furthermore, they have been complemented with an ab initio study of its elastic properties at different pressures. Calculated total and partial phonon density of states have allowed us to understand the contribution of the different atoms and structural units, YO12 dodecahedra and AlO6 octahedra, to the vibrational modes. The calculated infrared-active modes and their pressure dependence are also reported. Finally, the pressure dependences of the, elastic constants and the mechanical stability of the perovskite structure have been analyzed in detail, showing that this phase is mechanically stable until 92 GPa. In fact, experimental results up to 30 GPa show no evidence of any phase transition. A previously proposed possible phase transition in YAlO3 above 80 GPa is also discussed.This research was partially supported by MINECO (MAT2013-46649-C4-2/3/4-P, MAT2015-71070-REDC, and MAT2016-75586-C4-2/3/4-P) and by EU-FEDER funds. M.A.H.-R. thanks MINECO for an FPI grant (BES-2014-068666).Hernández-Rodríguez, M.; Monteseguro, V.; Lozano-Gorrín, A.; Manjón, F.; González-Platas, J.; Rodríguez-Hernández, P.; Muñoz, A.... (2017). Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures. The Journal of Physical Chemistry C. 121(28):15353-15367. https://doi.org/10.1021/acs.jpcc.7b04245S15353153671212

Structural and Lattice-Dynamical Properties of Tb2O3 under Compression: A Comparative Study with Rare Earth and Related Sesquioxides

[EN] We report a joint experimental and theoretical investigation of the high pressure structural and vibrational properties of terbium sesquioxide (Tb2O3). Powder X-ray diffraction and Raman scattering measurements show that cubic Ia (3 ) over bar (C-type) Tb2O3 undergoes two phase transitions up to 25 GPa. We observe a first irreversible reconstructive transition to the monoclinic C2/m (B-type) phase at similar to 7 GPa and a subsequent reversible displacive transition from the monoclinic to the trigonal P (3) over bar m1 (A-type) phase at similar to I-2 GPa. Thus, Tb2O3 is found to follow the well- known C -> B -> A phase transition sequence found in other cubic rare earth sesquioxides with cations of larger atomic mass than Tb. Our ab initio theoretical calculations predict phase transition pressures and bulk moduli for the three phases in rather good agreement with experimental results. Moreover, Raman-active modes of the three phases have been monitored as a function of pressure, while lattice-dynamics calculations have allowed us to confirm the assignment of the experimental phonon modes in the C- and A-type phases as well as to make a tentative assignment of the symmetry of most vibrational modes in the B-type phase. Finally, we extract the bulk moduli and the Raman-active mode frequencies together with their pressure coefficients for the three phases of Tb2O3 . These results are thoroughly compared and discussed in relation to those reported for rare earth and other related sesquioxides as well as with new calculations for selected sesquioxides. It is concluded that the evolution of the volume and bulk modulus of all the three phases of these technologically relevant compounds exhibit a nearly linear trend with respect to the third power of the ionic radii of the cations and that the values of the bulk moduli for the three phases depend on the filling of the f orbitals.The authors are thankful for the financial support of Generalitat Valenciana under Project PROMETEO 2018/123-EFIMAT and of the Spanish Ministerio de Economia y Competitividad under Projects MAT2015-71035-R, MAT2016-75586-C4-2/3/4-P, and FIS2017-2017-83295-P as well as MALTA Consolider Team research network under project RED2018-102612-T. J.A.S. also acknowledges the Ramon y Cajal program for funding support through RYC-2015-17482. A.M. and P.R.-H. acknowledge computing time provided by Red Española de Supercomputación (RES) and the MALTA Consolider Team cluster. HP-XRD experiments were performed at MPSD beamline of Alba Synchrotron (experiment no. 2016071772). We would like to thank Oriol Blázquez (Universitat de Barcelona) for his contribution to the Raman measurements.Ibañez, J.; Sans-Tresserras, JÁ.; Cuenca-Gotor, VP.; Oliva, R.; Gomis, O.; Rodríguez-Hernández, P.; Muñoz, A.... (2020). Structural and Lattice-Dynamical Properties of Tb2O3 under Compression: A Comparative Study with Rare Earth and Related Sesquioxides. Inorganic Chemistry. 59(14):9648-9666. https://doi.org/10.1021/acs.inorgchem.0c00834S964896665914Pan, T.-M., Chen, F.-H., & Jung, J.-S. (2010). Structural and electrical characteristics of high-k Tb2O3 and Tb2TiO5 charge trapping layers for nonvolatile memory applications. Journal of Applied Physics, 108(7), 074501. doi:10.1063/1.3490179Kao, C. H., Liu, K. C., Lee, M. H., Cheng, S. N., Huang, C. H., & Lin, W. K. (2012). High dielectric constant terbium oxide (Tb2O3) dielectric deposited on strained-Si:C. Thin Solid Films, 520(8), 3402-3405. doi:10.1016/j.tsf.2011.10.173Gray, N. W., Prestgard, M. C., & Tiwari, A. (2014). Tb2O3 thin films: An alternative candidate for high-k dielectric applications. Applied Physics Letters, 105(22), 222903. doi:10.1063/1.4903072Geppert, I., Eizenberg, M., Bojarczuk, N. A., Edge, L. F., Copel, M., & Guha, S. (2010). Determination of band offsets, chemical bonding, and microstructure of the (TbxSc1−x)2O3/Si system. Journal of Applied Physics, 108(2), 024105. doi:10.1063/1.3427554Belaya, S. V., Bakovets, V. V., Boronin, A. I., Koshcheev, S. V., Lobzareva, M. N., Korolkov, I. V., & Stabnikov, P. A. (2014). Terbium oxide films grown by chemical vapor deposition from terbium(III) dipivaloylmethanate. Inorganic Materials, 50(4), 379-386. doi:10.1134/s0020168514040037Bakovets, V. V., Belaya, S. V., Lobzareva, M. N., & Maksimovskii, E. A. (2014). Kinetics of terbium oxide film growth from Tb(dpm)3 vapor. Inorganic Materials, 50(6), 576-581. doi:10.1134/s0020168514060016ZINKEVICH, M. (2007). Thermodynamics of rare earth sesquioxides. Progress in Materials Science, 52(4), 597-647. doi:10.1016/j.pmatsci.2006.09.002Warshaw, I., & Roy, R. (1961). POLYMORPHISM OF THE RARE EARTH SESQUIOXIDES1. The Journal of Physical Chemistry, 65(11), 2048-2051. doi:10.1021/j100828a030Brauer, G., & Pfeiffer, B. (1965). Mischphasen aus Praseodym(III)-oxid und Terbium(III)-oxid. Zeitschrift f�r anorganische und allgemeine Chemie, 341(5-6), 237-243. doi:10.1002/zaac.19653410503Shevthenko, A. V., & Lopato, L. M. (1985). DTA method applikation to the highest refractory oxide systems investigation. Thermochimica Acta, 93, 537-540. doi:10.1016/0040-6031(85)85135-2Hoekstra, H. R., & Gingerich, K. A. (1964). High-Pressure B-Type Polymorphs of Some Rare-Earth Sesquioxides. Science, 146(3648), 1163-1164. doi:10.1126/science.146.3648.1163Sawyer, J. O., Hyde, B. G., & Eyring, L. (1965). Pressure and Polymorphism in the Rare Earth Sesquioxides. Inorganic Chemistry, 4(3), 426-427. doi:10.1021/ic50025a043Manjón, F., Sans, J., Ibáñez, J., & Pereira, A. (2019). Pressure-Induced Phase Transitions in Sesquioxides. Crystals, 9(12), 630. doi:10.3390/cryst9120630Jiang, S., Liu, J., Lin, C., Bai, L., Xiao, W., Zhang, Y., … Tang, L. (2010). Pressure-induced phase transition in cubic Lu2O3. Journal of Applied Physics, 108(8), 083541. doi:10.1063/1.3499301Lin, C.-M., Wu, K.-T., Hung, T.-L., Sheu, H.-S., Tsai, M.-H., Lee, J.-F., & Lee, J.-J. (2010). Phase transitions in under high pressure. Solid State Communications, 150(33-34), 1564-1569. doi:10.1016/j.ssc.2010.05.046Meyer, C., Sanchez, J. P., Thomasson, J., & Itié, J. P. (1995). Mössbauer and energy-dispersive x-ray-diffraction studies of the pressure-induced crystallographic phase transition inC-typeYb2O3. Physical Review B, 51(18), 12187-12193. doi:10.1103/physrevb.51.12187Pandey, S. D., Samanta, K., Singh, J., Sharma, N. D., & Bandyopadhyay, A. K. (2013). Anharmonic behavior and structural phase transition in Yb2O3. AIP Advances, 3(12), 122123. doi:10.1063/1.4858421Sahu, P. C., Lonappan, D., & Shekar, N. V. C. (2012). High Pressure Structural Studies on Rare-Earth Sesquioxides. Journal of Physics: Conference Series, 377, 012015. doi:10.1088/1742-6596/377/1/012015Irshad, K. A., Anees, P., Sahoo, S., Sanjay Kumar, N. R., Srihari, V., Kalavathi, S., & Chandra Shekar, N. V. (2018). Pressure induced structural phase transition in rare earth sesquioxide Tm2O3: Experiment and ab initio calculations. Journal of Applied Physics, 124(15), 155901. doi:10.1063/1.5049223Yan, D., Wu, P., Zhang, S. P., Liang, L., Yang, F., Pei, Y. L., & Chen, S. (2013). Assignments of the Raman modes of monoclinic erbium oxide. Journal of Applied Physics, 114(19), 193502. doi:10.1063/1.4831663Ren, X., Yan, X., Yu, Z., Li, W., & Wang, L. (2017). Photoluminescence and phase transition in Er2O3 under high pressure. Journal of Alloys and Compounds, 725, 941-945. doi:10.1016/j.jallcom.2017.07.219Guo, Q., Zhao, Y., Jiang, C., Mao, W. L., Wang, Z., Zhang, J., & Wang, Y. (2007). Pressure-Induced Cubic to Monoclinic Phase Transformation in Erbium Sesquioxide Er2O3. Inorganic Chemistry, 46(15), 6164-6169. doi:10.1021/ic070154gLonappan, D., Shekar, N. V. C., Ravindran, T. R., & Sahu, P. C. (2010). High-pressure phase transition in Ho2O3. Materials Chemistry and Physics, 120(1), 65-67. doi:10.1016/j.matchemphys.2009.10.022Jiang, S., Liu, J., Li, X., Bai, L., Xiao, W., Zhang, Y., … Tang, L. (2011). Phase transformation of Ho2O3at high pressure. Journal of Applied Physics, 110(1), 013526. doi:10.1063/1.3603027Pandey, S. D., Samanta, K., Singh, J., Sharma, N. D., & Bandyopadhyay, A. K. (2014). Raman scattering of rare earth sesquioxide Ho2O3: A pressure and temperature dependent study. Journal of Applied Physics, 116(13), 133504. doi:10.1063/1.4896832Yan, X., Ren, X., He, D., Chen, B., & Yang, W. (2014). Mechanical behaviors and phase transition of Ho2O3nanocrystals under high pressure. Journal of Applied Physics, 116(3), 033507. doi:10.1063/1.4890341Sharma, N. D., Singh, J., Dogra, S., Varandani, D., Poswal, H. K., Sharma, S. M., & Bandyopadhyay, A. K. (2011). Pressure-induced anomalous phase transformation in nano-crystalline dysprosium sesquioxide. Journal of Raman Spectroscopy, 42(3), 438-444. doi:10.1002/jrs.2720Jiang, S., Liu, J., Lin, C., Bai, L., Zhang, Y., Li, X., … Wang, H. (2013). Structural transformations in cubic Dy2O3 at high pressures. Solid State Communications, 169, 37-41. doi:10.1016/j.ssc.2013.06.027Chen, H., He, C., Gao, C., Ma, Y., Zhang, J., Wang, X., … Zou, G. (2007). The structural transition of Gd2O3nanoparticles induced by high pressure. Journal of Physics: Condensed Matter, 19(42), 425229. doi:10.1088/0953-8984/19/42/425229Hai-Yong, C., Chun-Yuan, H., Chun-Xiao, G., Jia-Hua, Z., Shi-Yong, G., Hong-Liang, L., … Guang-Tian, Z. (2007). Structural Transition of Gd 2 O 3  :Eu Induced by High Pressure. Chinese Physics Letters, 24(1), 158-160. doi:10.1088/0256-307x/24/1/043Zhang, F. X., Lang, M., Wang, J. W., Becker, U., & Ewing, R. C. (2008). Structural phase transitions of cubicGd2O3at high pressures. Physical Review B, 78(6). doi:10.1103/physrevb.78.064114Dilawar, N., Varandani, D., Mehrotra, S., Poswal, H. K., Sharma, S. M., & Bandyopadhyay, A. K. (2008). Anomalous high pressure behaviour in nanosized rare earth sesquioxides. Nanotechnology, 19(11), 115703. doi:10.1088/0957-4484/19/11/115703Bai, L., Liu, J., Li, X., Jiang, S., Xiao, W., Li, Y., … Zhang, D. (2009). Pressure-induced phase transformations in cubic Gd2O3. Journal of Applied Physics, 106(7), 073507. doi:10.1063/1.3236580Zou, X., Gong, C., Liu, B., Li, Q., Li, Z., Liu, B., … Song, H. (2011). X-ray diffraction of cubic Gd2 O3 /Er under high pressure. physica status solidi (b), 248(5), 1123-1127. doi:10.1002/pssb.201000706Zhang, C. C., Zhang, Z. M., Dai, R. C., Wang, Z. P., & Ding, Z. J. (2011). High Pressure Luminescence and Raman Studies on the Phase Transition of Gd2O3:Eu3+ Nanorods. Journal of Nanoscience and Nanotechnology, 11(11), 9887-9891. doi:10.1166/jnn.2011.5228Yang, X., Li, Q., Liu, Z., Bai, X., Song, H., Yao, M., … Liu, B. (2013). Pressure-Induced Amorphization in Gd2O3/Er3+ Nanorods. The Journal of Physical Chemistry C, 117(16), 8503-8508. doi:10.1021/jp312705uChen, G., Haire, R. G., & Peterson, J. R. (1991). Effect of pressure on cubic (C-type) Eu2O3studied via Eu3+luminescence. High Pressure Research, 6(6), 371-377. doi:10.1080/08957959208201045Chen, G., Stump, N. ., Haire, R. ., & Peterson, J. . (1992). Study of the phase behavior of Eu2O3 under pressure via luminescence of Eu3+. Journal of Alloys and Compounds, 181(1-2), 503-509. doi:10.1016/0925-8388(92)90347-cDilawar, N., Varandani, D., Pandey, V. P., Kumar, M., Shivaprasad, S. M., Sharma, P. K., & Bandyopadhyay, A. K. (2006). Structural Transition in Nanostructured Eu2O3 Under High Pressures. Journal of Nanoscience and Nanotechnology, 6(1), 105-113. doi:10.1166/jnn.2006.17913Sheng, J., Li-Gang, B., Jing, L., Wan-Sheng, X., Xiao-Dong, L., Yan-Chun, L., … Li-Rong, Z. (2009). The Phase Transition of Eu 2 O 3 under High Pressures. Chinese Physics Letters, 26(7), 076101. doi:10.1088/0256-307x/26/7/076101Irshad, K. A., Chandra Shekar, N. V., Srihari, V., Pandey, K. K., & Kalavathi, S. (2017). High pressure structural phase transitions in Ho: Eu2O3. Journal of Alloys and Compounds, 725, 911-915. doi:10.1016/j.jallcom.2017.07.224Yu, Z., Wang, Q., Ma, Y., & Wang, L. (2017). X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure. Journal of Alloys and Compounds, 701, 542-548. doi:10.1016/j.jallcom.2017.01.143Guo, Q., Zhao, Y., Jiang, C., Mao, W. L., & Wang, Z. (2008). Phase transformation in Sm2O3 at high pressure: In situ synchrotron X-ray diffraction study and ab initio DFT calculation. Solid State Communications, 145(5-6), 250-254. doi:10.1016/j.ssc.2007.11.019Jiang, S., Liu, J., Lin, C., Li, X., & Li, Y. (2013). High-pressure x-ray diffraction and Raman spectroscopy of phase transitions in Sm2O3. Journal of Applied Physics, 113(11), 113502. doi:10.1063/1.4795504Liu, D., Lei, W., Li, Y., Ma, Y., Hao, J., Chen, X., … Zou, G. (2009). High-Pressure Structural Transitions of Sc2O3by X-ray Diffraction, Raman Spectra, and Ab Initio Calculations. Inorganic Chemistry, 48(17), 8251-8256. doi:10.1021/ic900889vYusa, H., Tsuchiya, T., Sata, N., & Ohishi, Y. (2009). High-Pressure Phase Transition to the Gd2S3 Structure in Sc2O3: A New Trend in Dense Structures in Sesquioxides. Inorganic Chemistry, 48(16), 7537-7543. doi:10.1021/ic9001253Ovsyannikov, S. V., Bykova, E., Bykov, M., Wenz, M. D., Pakhomova, A. S., Glazyrin, K., … Dubrovinsky, L. (2015). Structural and vibrational properties of single crystals of Scandia, Sc2O3 under high pressure. Journal of Applied Physics, 118(16), 165901. doi:10.1063/1.4933391Husson, E., Proust, C., Gillet, P., & Itié, J. . (1999). Phase transitions in yttrium oxide at high pressure studied by Raman spectroscopy. Materials Research Bulletin, 34(12-13), 2085-2092. doi:10.1016/s0025-5408(99)00205-6Bai, X., Song, H. W., Liu, B. B., Hou, Y. Y., Pan, G. H., & Ren, X. G. (2008). Effects of High Pressure on the Luminescent Properties of Nanocrystalline and Bulk Y2O3:Eu3+. Journal of Nanoscience and Nanotechnology, 8(3), 1404-1409. doi:10.1166/jnn.2008.18204Jovanić, B. R., Dramićanin, M., Viana, B., Panić, B., & Radenković, B. (2008). High-pressure optical studies of Y2O3:Eu3+nanoparticles. Radiation Effects and Defects in Solids, 163(12), 925-931. doi:10.1080/10420150802082705Wang, L., Pan, Y., Ding, Y., Yang, W., Mao, W. L., Sinogeikin, S. V., … Mao, H. (2009). High-pressure induced phase transitions of Y2O3 and Y2O3:Eu3+. Applied Physics Letters, 94(6), 061921. doi:10.1063/1.3082082Wang, L., Yang, W., Ding, Y., Ren, Y., Xiao, S., Liu, B., … Mao, H. (2010). Size-Dependent Amorphization of NanoscaleY2O3at High Pressure. Physical Review Letters, 105(9). doi:10.1103/physrevlett.105.095701Halevy, I., Carmon, R., Winterrose, M. L., Yeheskel, O., Tiferet, E., & Ghose, S. (2010). Pressure-induced structural phase transitions in Y2O3sesquioxide. Journal of Physics: Conference Series, 215, 012003. doi:10.1088/1742-6596/215/1/012003Dai, R. C., Zhang, Z. M., Zhang, C. C., & Ding, Z. J. (2010). Photoluminescence and Raman Studies of Y2O3:Eu3+ Nanotubes Under High Pressure. Journal of Nanoscience and Nanotechnology, 10(11), 7629-7633. doi:10.1166/jnn.2010.2752DAI, R., WANG, Z., ZHANG, Z., & DING, Z. (2010). Photoluminescence study of SiO2 coated Eu3+:Y2O3 core-shells under high pressure. Journal of Rare Earths, 28, 241-245. doi:10.1016/s1002-0721(10)60275-xYusa, H., Tsuchiya, T., Sata, N., & Ohishi, Y. (2010). Dense Yttria Phase Eclipsing the A-Type Sesquioxide Structure: High-Pressure Experiments and ab initio Calculations. Inorganic Chemistry, 49(10), 4478-4485. doi:10.1021/ic100042zBose, P. P., Gupta, M. K., Mittal, R., Rols, S., Achary, S. N., Tyagi, A. K., & Chaplot, S. L. (2012). High Pressure Phase Transitions in Yttria, Y2O3. Journal of Physics: Conference Series, 377, 012036. doi:10.1088/1742-6596/377/1/012036Srivastava, A. M., Renero-Lecuna, C., Santamaría-Pérez, D., Rodríguez, F., & Valiente, R. (2014). Pressure-induced Pr3+ 3P0 luminescence in cubic Y2O3. Journal of Luminescence, 146, 27-32. doi:10.1016/j.jlumin.2013.09.028Yamanaka, T., Nagai, T., Okada, T., & Fukuda, T. (2005). Structure change of Mn2O3under high pressure and pressure-induced transition. Zeitschrift für Kristallographie - Crystalline Materials, 220(11), 938-945. doi:10.1524/zkri.2005.220.11_2005.938Santillán, J., Shim, S.-H., Shen, G., & Prakapenka, V. B. (2006). High-pressure phase transition in Mn2O3: Application for the crystal structure and preferred orientation of the CaIrO3type. Geophysical Research Letters, 33(15). doi:10.1029/2006gl026423Shim, S.-H., LaBounty, D., & Duffy, T. S. (2011). Raman spectra of bixbyite, Mn2O3, up to 40 GPa. Physics and Chemistry of Minerals, 38(9), 685-691. doi:10.1007/s00269-011-0441-4Hong, F., Yue, B., Hirao, N., Liu, Z., & Chen, B. (2017). Significant improvement in Mn2O3 transition metal oxide electrical conductivity via high pressure. Scientific Reports, 7(1). doi:10.1038/srep44078Yusa, H., Tsuchiya, T., Sata, N., & Ohishi, Y. (2008). Rh2O3(II)-type structures inGa2O3andIn2O3under high pressure: Experiment and theory. Physical Review B, 77(6). doi:10.1103/physrevb.77.064107Liu, D., Lei, W. W., Zou, B., Yu, S. D., Hao, J., Wang, K., … Zou, G. T. (2008). High-pressure x-ray diffraction and Raman spectra study of indium oxide. Journal of Applied Physics, 104(8), 083506. doi:10.1063/1.2999369Qi, J., Liu, J. F., He, Y., Chen, W., & Wang, C. (2011). Compression behavior and phase transition of cubic In2O3 nanocrystals. Journal of Applied Physics, 109(6), 063520. doi:10.1063/1.3561363Garcia-Domene, B., Ortiz, H. M., Gomis, O., Sans, J. A., Manjón, F. J., Muñoz, A., … Tyagi, A. K. (2012). High-pressure lattice dynamical study of bulk and nanocrystalline In2O3. Journal of Applied Physics, 112(12), 123511. doi:10.1063/1.4769747García-Domene, B., Sans, J. A., Gomis, O., Manjón, F. J., Ortiz, H. M., Errandonea, D., … Segura, A. (2014). Pbca-Type In2O3: The High-Pressure Post-Corundum phase at Room Temperature. The Journal of Physical Chemistry C, 118(35), 20545-20552. doi:10.1021/jp5061599Gomis, O., Santamaría-Pérez, D., Ruiz-Fuertes, J., Sans, J. A., Vilaplana, R., Ortiz, H. M., … Mollar, M. (2014). High-pressure structural and elastic properties of Tl2O3. Journal of Applied Physics, 116(13), 133521. doi:10.1063/1.4897241Mcclure, J. P. High Pressure Phase Transistions in the Lanthanide Sesquioxides. Ph.D. Thesis, University of Nevada, Las Vegas, 2009, pp 1–154.Hirosaki, N., Ogata, S., & Kocer, C. (2003). Ab initio calculation of the crystal structure of the lanthanide Ln2O3 sesquioxides. Journal of Alloys and Compounds, 351(1-2), 31-34. doi:10.1016/s0925-8388(02)01043-5Marsella, L., & Fiorentini, V. (2004). Structure and stability of rare-earth and transition-metal oxides. Physical Review B, 69(17). doi:10.1103/physrevb.69.172103Petit, L., Svane, A., Szotek, Z., & Temmerman, W. M. (2005). First-principles study of rare-earth oxides. Physical Review B, 72(20). doi:10.1103/physrevb.72.205118WU, B., ZINKEVICH, M., WANG, C., & ALDINGER, F. (2006). Ab initio energetic study of oxide ceramics with rare-earth elements. Rare Metals, 25(5), 549-555. doi:10.1016/s1001-0521(06)60097-1Singh, N., Saini, S. M., Nautiyal, T., & Auluck, S. (2006). Electronic structure and optical properties of rare earth sesquioxides (R2O3, R=La, Pr, and Nd). Journal of Applied Physics, 100(8), 083525. doi:10.1063/1.2353267Mikami, M., & Nakamura, S. (2006). Electronic structure of rare-earth sesquioxides and oxysulfides. Journal of Alloys and Compounds, 408-412, 687-692. doi:10.1016/j.jallcom.2005.01.068Wu, B., Zinkevich, M., Aldinger, F., Wen, D., & Chen, L. (2007). Ab initio study on structure and phase transition of A- and B-type rare-earth sesquioxides Ln2O3 (Ln=La–Lu, Y, and Sc) based on density function theory. Journal of Solid State Chemistry, 180(11), 3280-3287. doi:10.1016/j.jssc.2007.09.022Rahm, M., & Skorodumova, N. V. (2009). Phase stability of the rare-earth sesquioxides under pressure. Physical Review B, 80(10). doi:10.1103/physrevb.80.104105Jiang, H., Gomez-Abal, R. I., Rinke, P., & Scheffler, M. (2009). Localized and Itinerant States in Lanthanide Oxides United byGW @ LDA+U. Physical Review Letters, 102(12). doi:10.1103/physrevlett.102.126403Gillen, R., Clark, S. J., & Robertson, J. (2013). Nature of the electronic band gap in lanthanide oxides. Physical Review B, 87(12). doi:10.1103/physrevb.87.125116Richard, D., Muñoz, E. L., Rentería, M., Errico, L. A., Svane, A., & Christensen, N. E. (2013). AbinitioLSDA and LSDA+Ustudy of pure and Cd-doped cubic lanthanide sesquioxides. Physical Review B, 88(16). doi:10.1103/physrevb.88.165206Richard, D., Errico, L. A., & Rentería, M. (2016). Structural properties and the pressure-induced C → A phase transition of lanthanide sesquioxides from DFT and DFT + U calculations. Journal of Alloys and Compounds, 664, 580-589. doi:10.1016/j.jallcom.2015.12.236Ogawa, T., Otani, N., Yokoi, T., Fisher, C. A. J., Kuwabara, A., Moriwake, H., … Takata, M. (2018). Density functional study of the phase stability and Raman spectra of Yb2O3, Yb2SiO5 and Yb2Si2O7 under pressure. Physical Chemistry Chemical Physics, 20(24), 16518-16527. doi:10.1039/c8cp02497aPathak, A. K., & Vazhappilly, T. (2018). Ab Initio Study on Structure, Elastic, and Mechanical Properties of Lanthanide Sesquioxides. physica status solidi (b), 255(6), 1700668. doi:10.1002/pssb.201700668Lonappan, D., Chandra Shekar, N. V., Sahu, P. C., Kumar, J., Paul, R., & Paul, P. (2010). Unusually large structural stability of terbium oxide phase under high pressure. Journal of Alloys and Compounds, 490(1-2), 47-49. doi:10.1016/j.jallcom.2009.10.068Veber, P., Velázquez, M., Gadret, G., Rytz, D., Peltz, M., & Decourt, R. (2015). Flux growth at 1230 °C of cubic Tb2O3single crystals and characterization of their optical and magnetic properties. CrystEngComm, 17(3), 492-497. doi:10.1039/c4ce02006eIbáñez,

Upconversion dynamics in Er3+ dopped fluoroindate glasses

Publicado

1000 K optical ratiometric thermometer based on Er3+ luminescence in yttrium gallium garnet

The temperature dependence of the Er3+ green luminescence in Y3Ga5O12 crystal were analysed under ultraviolet and near-infrared laser excitations for optical sensing purposes. Changes in the relative green emission intensities from the 2H11/2 and 4S3/2 thermally-coupled multiplets to the 4I15/2 ground state were measured from room temperature up to 1000 K. The calibrated temperature scale shows a maximum in the absolute thermal sensitivity of ~23.9 × 10−4K−1 at 580 K and a relative thermal sensitivity of ~1.36%K−1 at RT, combining results for both blue and near-infrared laser excitations. The excellent results obtained, compared with other Er3+-based optical temperature sensors, are a consequence of the advantages of garnet crystals as optically efficient hosts that, apart from an impressive capability to be synthesized both as bulk and fiber forms, allow extending the long working temperature range up to 1000 K, and beyond, to the melting point limit close to 2000 K. In addition, the use of green emissions for the temperature calibration, with negligible black-body radiation disturbance, only needs a low-cost, basic setup that uses commercially available lenses, lasers and detectors. All these facts support the Er3+-doped Y3Ga5O12 garnet crystal as a potential candidate as temperature sensor, showing large sensitivity and good temperature resolution for ultra-high temperature industrial applications.publishe

Smart composite films of nanometric thickness based on copper-iodine coordination polymers. Toward sensors

One-pot reactions between CuI and methyl or methyl 2-amino-isonicotinate give rise to the formation of two coordination polymers (CPs) based on double zig-zag Cu2I2 chains. The presence of a NH2 group in the isonicotinate ligand produces different supramolecular interactions affecting the Cu-Cu distances and symmetry of the Cu2I2 chains. These structural variations significantly modulate their physical properties. Thus, both CPs are semiconductors and also show reversible thermo/mechanoluminescence. X-ray diffraction studies carried out under different temperature and pressure conditions in combination with theoretical calculations have been used to rationalize the multi-stimuli-responsive properties. Importantly, a bottom-up procedure based on fast precipitation leads to nanofibers of both CPs. The dimensions of these nanofibres enable the preparation of thermo/mechanochromic film composites with polyvinylidene difluoride. These films are tens of nanometers in thickness while being centimeters in length, representing smaller thicknesses so far reported for thin-film composites. This nanomaterial integration of CPs could represent a source of alternative nanomaterials for opto-electronic device fabrication