{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T03:31:07Z","timestamp":1773027067816,"version":"3.50.1"},"reference-count":80,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,4,20]],"date-time":"2021-04-20T00:00:00Z","timestamp":1618876800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["192346071"],"award-info":[{"award-number":["192346071"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>TiO2 thin films deposited by atomic layer deposition (ALD) at low temperatures (&lt;100 \u00b0C) are, in general, amorphous and exhibit a smaller refractive index in comparison to their crystalline counterparts. Nonetheless, low-temperature ALD is needed when the substrates or templates are based on polymeric materials, as the deposition has to be performed below their glass transition or melting temperatures. This is the case for photonic crystals generated via ALD infiltration of self-assembled polystyrene templates. When heated up, crystal phase transformations take place in the thin films or photonic structures, and the accompanying volume reduction as well as the burn-out of residual impurities can lead to mechanical instability. The introduction of cation doping (e.g., Al or Nb) in bulk TiO2 parts is known to alter phase transitions and to stabilize crystalline phases. In this work, we have developed low-temperature ALD super-cycles to introduce Al2O3 into TiO2 thin films and photonic crystals. The aluminum oxide content was adjusted by varying the TiO2:Al2O3 internal loop ratio within the ALD super-cycle. Both thin films and inverse opal photonic crystal structures were subjected to thermal treatments ranging from 200 to 1200 \u00b0C and were characterized by in- and ex-situ X-ray diffraction, spectroscopic ellipsometry, and spectroscopic reflectance measurements. The results show that the introduction of alumina affects the crystallization and phase transition temperatures of titania as well as the optical properties of the inverse opal photonic crystals (iPhC). The thermal stability of the titania iPhCs was increased by the alumina introduction, maintaining their photonic bandgap even after heat treatment at 900 \u00b0C and outperforming the pure titania, with the best results being achieved with the super-cycles corresponding to an estimated alumina content of 26 wt.%.<\/jats:p>","DOI":"10.3390\/nano11041053","type":"journal-article","created":{"date-parts":[[2021,4,20]],"date-time":"2021-04-20T13:58:04Z","timestamp":1618927084000},"page":"1053","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Influence of Alumina Addition on the Optical Properties and the Thermal Stability of Titania Thin Films and Inverse Opals Produced by Atomic Layer Deposition"],"prefix":"10.3390","volume":"11","author":[{"given":"Martin","family":"Waleczek","sequence":"first","affiliation":[{"name":"Institute of Nanostructure and Solid State Physics &amp; Center for Hybrid Nanostructures, Universit\u00e4t Hamburg, Luruper Chausse 149, 22761 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2385-3693","authenticated-orcid":false,"given":"Jolien","family":"Dendooven","sequence":"additional","affiliation":[{"name":"Department of Solid State Sciences, COCOON Group, Ghent University, Krijgslaan 281\/S1, B-9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pavel","family":"Dyachenko","sequence":"additional","affiliation":[{"name":"Holoeye Photonics AG, Volmerstrasse 1, 12489 Berlin, Germany"},{"name":"Institute of Optical and Electronic Materials, Hamburg University of Technology, Ei\u00dfendorfer Str. 38, 21073 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander Y.","family":"Petrov","sequence":"additional","affiliation":[{"name":"Institute of Optical and Electronic Materials, Hamburg University of Technology, Ei\u00dfendorfer Str. 38, 21073 Hamburg, Germany"},{"name":"Institute of Hydrogen Technology, Helmholtz-Zentrum hereon, Max-Planck-Stra\u00dfe 1, D-21502 Geesthacht, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manfred","family":"Eich","sequence":"additional","affiliation":[{"name":"Institute of Optical and Electronic Materials, Hamburg University of Technology, Ei\u00dfendorfer Str. 38, 21073 Hamburg, Germany"},{"name":"Institute of Hydrogen Technology, Helmholtz-Zentrum hereon, Max-Planck-Stra\u00dfe 1, D-21502 Geesthacht, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert H.","family":"Blick","sequence":"additional","affiliation":[{"name":"Institute of Nanostructure and Solid State Physics &amp; Center for Hybrid Nanostructures, Universit\u00e4t Hamburg, Luruper Chausse 149, 22761 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christophe","family":"Detavernier","sequence":"additional","affiliation":[{"name":"Department of Solid State Sciences, COCOON Group, Ghent University, Krijgslaan 281\/S1, B-9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kornelius","family":"Nielsch","sequence":"additional","affiliation":[{"name":"Institute of Materials Science, Technical University Dresden, Helmholtzstr. 10, 01069 Dresden, Germany"},{"name":"IFW Dresden, Institute for Metallic Materials, Helmholtzstr. 20, 01069 Dresden, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4032-2795","authenticated-orcid":false,"given":"Kaline P.","family":"Furlan","sequence":"additional","affiliation":[{"name":"Institute of Nanostructure and Solid State Physics &amp; Center for Hybrid Nanostructures, Universit\u00e4t Hamburg, Luruper Chausse 149, 22761 Hamburg, Germany"},{"name":"Institute of Advanced Ceramics, Hamburg University of Technology, Denickest. 15, 21073 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0292-0970","authenticated-orcid":false,"given":"Robert","family":"Zierold","sequence":"additional","affiliation":[{"name":"Institute of Nanostructure and Solid State Physics &amp; Center for Hybrid Nanostructures, Universit\u00e4t Hamburg, Luruper Chausse 149, 22761 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6109","DOI":"10.1039\/C5TC01083G","article-title":"Artificial opal photonic crystals and inverse opal structures\u2014Fundamentals and applications from optics to energy storage","volume":"3","author":"Armstrong","year":"2015","journal-title":"J. Mater. Chem. C"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"46101","DOI":"10.1063\/1.5084138","article-title":"Highly selective photonic glass filter for saturated blue structural color","volume":"4","author":"Shang","year":"2019","journal-title":"APL Photonics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"7804","DOI":"10.1038\/s41598-018-26119-8","article-title":"Photonic glass for high contrast structural color","volume":"8","author":"Shang","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1016\/j.mattod.2016.03.004","article-title":"Structural color materials in evolution","volume":"19","author":"Shang","year":"2016","journal-title":"Mater. Today"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"945","DOI":"10.1039\/C9MH00101H","article-title":"Bio-Inspired intelligent structural color materials","volume":"6","author":"Shang","year":"2019","journal-title":"Mater. Horiz."},{"key":"ref_6","first-page":"1900428","article-title":"YSZ hollow sphere photonic glasses: Tailoring optical properties for highly saturated non-iridescent structural coloration","volume":"9","author":"Shang","year":"2019","journal-title":"Adv. Opt. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3353","DOI":"10.1016\/j.jeurceramsoc.2019.04.028","article-title":"Advancing the fabrication of YSZ-inverse photonic glasses for broadband omnidirectional reflector films","volume":"39","author":"Pasquarelli","year":"2019","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Arpin, K.A., Losego, M.D., Cloud, A.N., Ning, H., Mallek, J., Sergeant, N.P., Zhu, L., Yu, Z., Kalanyan, B., and Parsons, G.N. (2013). Three-Dimensional self-assembled photonic crystals with high temperature stability for thermal emission modification. Nat. Commun., 4.","DOI":"10.1038\/ncomms3630"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6589","DOI":"10.1021\/acs.langmuir.0c00051","article-title":"Colloidal photonic assemblies for colorful radiative cooling","volume":"36","author":"Kim","year":"2020","journal-title":"Langmuir"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"12282","DOI":"10.1073\/pnas.1509453112","article-title":"Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody","volume":"112","author":"Zhu","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1039\/C5CS00533G","article-title":"A colloidoscope of colloid-based porous materials and their uses","volume":"45","author":"Phillips","year":"2016","journal-title":"Chem. Soc. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6265","DOI":"10.1021\/cr400081d","article-title":"Advances in colloidal assembly: The design of structure and hierarchy in two and three dimensions","volume":"115","author":"Vogel","year":"2015","journal-title":"Chem. Rev."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"21301","DOI":"10.1063\/1.4757907","article-title":"Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends","volume":"113","author":"Miikkulainen","year":"2013","journal-title":"J. Appl. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"211102","DOI":"10.1063\/1.2387874","article-title":"High filling fraction gallium phosphide inverse opals by atomic layer deposition","volume":"89","author":"Graugnard","year":"2006","journal-title":"Appl. Phys. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2566","DOI":"10.1063\/1.1609240","article-title":"High-Filling-Fraction inverted ZnS opals fabricated by atomic layer deposition","volume":"83","author":"King","year":"2003","journal-title":"Appl. Phys. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2761","DOI":"10.1002\/adma.200500569","article-title":"ZnO inverse opals by chemical vapor deposition","volume":"17","author":"Golmayo","year":"2005","journal-title":"Adv. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"91101","DOI":"10.1063\/1.3216582","article-title":"Photonic bandgap engineering with inverse opal multistacks of different refractive index contrasts","volume":"95","author":"Hwang","year":"2009","journal-title":"Appl. Phys. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3562","DOI":"10.1021\/cm060263d","article-title":"Modification of opal photonic crystals using Al2O3 atomic layer deposition","volume":"18","author":"Sechrist","year":"2006","journal-title":"Chem. Mater."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"11260","DOI":"10.1016\/j.ceramint.2017.05.176","article-title":"Highly porous \u03b1-Al2O3 ceramics obtained by sintering atomic layer deposited inverse opals","volume":"43","author":"Furlan","year":"2017","journal-title":"Ceram. Int."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.apmt.2018.10.002","article-title":"Photonic materials for high-temperature applications: Synthesis and characterization by X-ray ptychographic tomography","volume":"13","author":"Furlan","year":"2018","journal-title":"Appl. Mater. Today"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Furlan, K.P., Krekeler, T., Ritter, M., Blick, R., Schneider, G.A., Nielsch, K., Zierold, R., and Jan\u00dfen, R. (2017). Low-Temperature mullite formation in ternary oxide coatings deposited by ALD for high-temperature applications. Adv. Mater. Interfaces, 4.","DOI":"10.1002\/admi.201700912"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3103","DOI":"10.1016\/j.jeurceramsoc.2015.04.041","article-title":"Enhanced structural and phase stability of titania inverse opals","volume":"35","author":"Pasquarelli","year":"2015","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1187","DOI":"10.1002\/adfm.200500841","article-title":"Sacrificial-Layer atomic layer deposition for fabrication of non-close-packed inverse-opal photonic crystals","volume":"16","author":"Graugnard","year":"2006","journal-title":"Adv. Funct. Mater."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1010","DOI":"10.1002\/adma.200400648","article-title":"TiO2 inverse opals fabricated using low-temperature atomic layer deposition","volume":"17","author":"King","year":"2005","journal-title":"Adv. Mater."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"03E107","DOI":"10.1116\/1.4979047","article-title":"Variation in the density, optical polarizabilities, and crystallinity of TiO2 thin films deposited via atomic layer deposition from 38 to 150 \u00b0C using the titanium tetrachloride-water reaction","volume":"35","author":"Piercy","year":"2017","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4022","DOI":"10.1109\/JSEN.2018.2819700","article-title":"A Comparative study of amorphous, anatase, rutile, and mixed phase TiO2 films by mist chemical vapor deposition and ultraviolet photodetectors applications","volume":"18","author":"Liu","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_27","first-page":"7529","article-title":"Deposited TiO2 thin films by atomic layer deposition (ALD) for optical properties","volume":"11","author":"Hussin","year":"2016","journal-title":"ARPN J. Eng. Appl. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"109335","DOI":"10.1016\/j.optmat.2019.109335","article-title":"Influence of phase composition on optical properties of TiO2: Dependence of refractive index and band gap on formation of TiO2-II phase in thin films","volume":"96","author":"Aarik","year":"2019","journal-title":"Opt. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1088\/0022-3727\/39\/1\/010","article-title":"Refractive index gradients in TiO2 thin films grown by atomic layer deposition","volume":"39","author":"Kasikov","year":"2006","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/S0040-6090(99)00938-4","article-title":"Reactive sputter deposition of titanium dioxide","volume":"360","author":"Dannenberg","year":"2000","journal-title":"Thin Solid Films"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1007\/s10853-010-5113-0","article-title":"Review of the anatase to rutile phase transformation","volume":"46","author":"Hanaor","year":"2011","journal-title":"J. Mater. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5179","DOI":"10.1016\/j.ceramint.2018.12.026","article-title":"Design guidelines for titania-silica-alumina ceramics with tuned anatase to rutile transformation","volume":"45","author":"Feltrin","year":"2019","journal-title":"Ceram. Int."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1016\/j.actamat.2004.09.038","article-title":"Dopant effect on grain boundary diffusivity in polycrystalline alumina","volume":"53","author":"Yoshida","year":"2005","journal-title":"Acta Mater."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11975","DOI":"10.1016\/j.ceramint.2015.05.162","article-title":"Grain growth suppression in alumina via doping and two-step sintering","volume":"41","author":"Galusek","year":"2015","journal-title":"Ceram. Int."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1557\/JMR.1997.0065","article-title":"Modification of the phase transition temperatures in titania doped with various cations","volume":"12","author":"Vargas","year":"1997","journal-title":"J. Mater. Res."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"22408","DOI":"10.1116\/1.5134743","article-title":"Atomic layer deposition of Nb-doped TiO2: Dopant incorporation and effect of annealing","volume":"38","author":"Berghuis","year":"2020","journal-title":"J. Vac. Sci. Technology A"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1644","DOI":"10.1557\/JMR.1998.0226","article-title":"Niobium-Titanium oxide powders obtained by laser-induced synthesis: Microstructure and structure evolution from diffraction data","volume":"13","author":"Depero","year":"1998","journal-title":"J. Mater. Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"853","DOI":"10.1063\/1.1487915","article-title":"Effects of Nb doping on the TiO2 anatase-to-rutile phase transition","volume":"92","author":"Arbiol","year":"2002","journal-title":"J. Appl. Phys."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Zhu, M.W., Ma, H.B., Jin, P.H., Jin, Y.N., Jia, N., Chen, H., and Liu, C.Z. (2020). An insight into the low doping efficiency of Al in sol\u2013gel-derived ZnO:Al films: Role of the dopant chemical state. Appl. Phys. A, 126.","DOI":"10.1007\/s00339-020-03670-8"},{"key":"ref_40","first-page":"13146","article-title":"High-Temperature stable inverse opal photonic crystals via mullite-sol-gel infiltration of direct photonic crystals","volume":"24","author":"Bueno","year":"2018","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1039\/C5MH00260E","article-title":"The evolution of \u2018sol-gel\u2019 chemistry as a technique for materials synthesis","volume":"3","author":"Danks","year":"2016","journal-title":"Mater. Horiz."},{"key":"ref_42","unstructured":"Carter, C.B., and Norton, M.G. (2007). Sols, gels, and organic chemistry. Ceramic Materials, Springer."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3723","DOI":"10.1021\/cm800280t","article-title":"Growth behavior of al-doped TiO2 thin films by atomic layer deposition","volume":"20","author":"Kim","year":"2008","journal-title":"Chem. Mater."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"253107","DOI":"10.1063\/1.4885415","article-title":"Density dependence of the room temperature thermal conductivity of atomic layer deposition-grown amorphous alumina (Al2O3)","volume":"104","author":"Gorham","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"L328","DOI":"10.1143\/JJAP.43.L328","article-title":"Investigation of silicon oxide thin films prepared by atomic layer deposition using SiH2Cl2 and O3 as the precursors","volume":"43","author":"Lee","year":"2004","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/S0040-6090(97)00404-5","article-title":"The dependence of hardness on the density of amorphous alumina thin films by PECVD","volume":"310","author":"Wang","year":"1997","journal-title":"Thin Solid Films"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2226","DOI":"10.1111\/j.1551-2916.2012.05156.x","article-title":"Stacking of ceramic inverse opals with different lattice constants","volume":"95","author":"Kubrin","year":"2012","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"182004","DOI":"10.1088\/1757-899X\/18\/18\/182004","article-title":"Towards ceramic 3DOM-materials as novel high-temperature reflective coatings and filters for thermophotovoltaics","volume":"18","author":"Kubrin","year":"2011","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"10466","DOI":"10.1021\/acsami.6b00827","article-title":"Bottom-Up fabrication of multilayer stacks of 3D photonic crystals from titanium dioxide","volume":"8","author":"Kubrin","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.tsf.2018.09.028","article-title":"Study of aluminium oxide thin films deposited by plasma-enhanced atomic layer deposition from tri-methyl-aluminium and dioxygen precursors: Investigation of interfacial and structural properties","volume":"666","author":"Lale","year":"2018","journal-title":"Thin Solid Films"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1186\/s11671-015-0757-y","article-title":"The impact of thickness and thermal annealing on refractive index for aluminum oxide thin films deposited by atomic layer deposition","volume":"10","author":"Wang","year":"2015","journal-title":"Nanoscale Res. Lett."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1021\/cm0304546","article-title":"Low-Temperature Al2O3 atomic layer deposition","volume":"16","author":"Groner","year":"2004","journal-title":"Chem. Mater."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"64314","DOI":"10.1063\/1.3327430","article-title":"Low temperature silicon dioxide by thermal atomic layer deposition: Investigation of material properties","volume":"107","author":"Hiller","year":"2010","journal-title":"J. Appl. Phys."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Hsu, C.-H., Chen, K.-T., Huang, P.-H., Wu, W.-Y., Zhang, X.-Y., Wang, C., Liang, L.-S., Gao, P., Qiu, Y., and Lien, S.-Y. (2020). Effect of annealing temperature on spatial atomic layer deposited titanium oxide and its application in perovskite solar cells. Nanomaterials, 10.","DOI":"10.3390\/nano10071322"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1007\/s10971-015-3829-7","article-title":"Adjustable refractive index of titania\u2013alumina thin films prepared from soluble precursor powders","volume":"77","author":"Hegmann","year":"2016","journal-title":"J. Sol Gel Sci. Technol."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Gon\u00e7alves, M.C., Pereira, J.C., Matos, J.C., and Vasconcelos, H.C. (2018). Photonic band gap and bactericide performance of amorphous sol-gel titania: An alternative to crystalline TiO\u2082. Molecules, 23.","DOI":"10.3390\/molecules23071677"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"73","DOI":"10.2478\/pjct-2013-0026","article-title":"Study of the anatase to rutile transformation kinetics of the modified TiO2","volume":"15","author":"Grzmil","year":"2013","journal-title":"Pol. J. Chem. Technol."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/S0040-6090(96)08848-7","article-title":"Correlation between the density of TiO2 films and their properties","volume":"286","author":"Ottermann","year":"1996","journal-title":"Thin Solid Films"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"L945","DOI":"10.1143\/JJAP.41.L945","article-title":"High anatase-rutile transformation temperature of anatase titania nanoparticles prepared by metalorganic chemical vapor deposition","volume":"41","author":"Sun","year":"2002","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.jcis.2010.04.005","article-title":"Rutile TiO2 inverse opal with photonic bandgap in the UV-visible range","volume":"348","author":"Li","year":"2010","journal-title":"J. Colloid Interface Sci."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1039\/JM9930301151","article-title":"Textural evolution and phase transformation in titania membranes: Part 2\u2014Supported membranes","volume":"3","author":"Kumar","year":"1993","journal-title":"J. Mater. Chem."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1039\/JM9930300917","article-title":"Textural stability of titania-alumina composite membranes","volume":"3","author":"Kumar","year":"1993","journal-title":"J. Mater. Chem."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"717","DOI":"10.2138\/am-1997-7-809","article-title":"Particle size effects on transformation kinetics and phase stability in nanocrystalline TiO2","volume":"82","author":"Gribb","year":"1997","journal-title":"Am. Mineral."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"3414","DOI":"10.1063\/1.1713231","article-title":"Phase transformation studies in TiO2 supporting different defect mechanisms in vacuum-reduced and hydrogen-reduced rutile","volume":"35","author":"Shannon","year":"1964","journal-title":"J. Appl. Phys."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1571","DOI":"10.1023\/A:1017515804370","article-title":"Kinetics of the anatase\u2013rutile transformation in TiO2 in the presence of Fe2O3","volume":"33","author":"Gennari","year":"1998","journal-title":"J. Mater. Sci."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"2556","DOI":"10.1557\/JMR.1998.0356","article-title":"Correlation between anatase-to-rutile transformation and grain growth in nanocrystalline titania powders","volume":"13","author":"Ding","year":"1998","journal-title":"J. Mater. Res."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"2867","DOI":"10.1016\/j.jeurceramsoc.2011.06.014","article-title":"Preparation and characterization of photocatalytic titania\u2013alumina composite membranes by sol\u2013gel methods","volume":"31","author":"Habibpanah","year":"2011","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"3932","DOI":"10.1557\/JMR.1999.0532","article-title":"Effects of cationic dopants on the phase transition temperature of titania prepared by the sol-gel method","volume":"14","author":"Vargas","year":"1999","journal-title":"J. Mater. Res."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1007\/BF00278028","article-title":"The influence of alumina dopant on the structural transformation of gel-derived nanometre titania powders","volume":"13","author":"Ding","year":"1994","journal-title":"J. Mater. Sci. Lett."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1111\/j.1151-2916.1988.tb05852.x","article-title":"Role of particle substructure in the sintering of monosized titania","volume":"71","author":"Edelson","year":"1988","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"97168","DOI":"10.1063\/1.4931925","article-title":"Controlled formation of anatase and rutile TiO2 thin films by reactive magnetron sputtering","volume":"5","author":"Rafieian","year":"2015","journal-title":"AIP Adv."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"1971","DOI":"10.1021\/acs.chemmater.7b05128","article-title":"Understanding the growth mechanisms of multilayered systems in atomic layer deposition process","volume":"30","author":"Wiegand","year":"2018","journal-title":"Chem. Mater."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"1532","DOI":"10.1111\/ijac.13021","article-title":"Properties and microstructural aspects of TiO2-doped sintered alumina-zirconia composite ceramics","volume":"15","author":"Khaskhoussi","year":"2018","journal-title":"Int. J. Appl. Ceram. Technol."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1007\/s10971-019-05057-5","article-title":"Mechanical strengths and thermal properties of titania-doped alumina aerogels and the application as high-temperature thermal insulator","volume":"91","author":"Gao","year":"2019","journal-title":"J. Sol Gel Sci. Technol."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"1702256","DOI":"10.1002\/adfm.201702256","article-title":"Understanding thermal insulation in porous, particulate materials","volume":"27","author":"Ruckdeschel","year":"2017","journal-title":"Adv. Funct. Mater."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"1701850","DOI":"10.1002\/adma.201701850","article-title":"Nanolattices: An emerging class of mechanical metamaterials","volume":"29","author":"Bauer","year":"2017","journal-title":"Adv. Mater."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/j.apsusc.2005.01.118","article-title":"Mechanical stress in ALD-Al2O3 films","volume":"252","author":"Krautheim","year":"2005","journal-title":"Appl. Surf. Sci."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"3546","DOI":"10.1111\/j.1551-2916.2008.02727.x","article-title":"Effects of milling and calcination temperature on the compressibility and sinterability of a nanocrystalline Al2O3-Y 3 Al5O12 composite powder","volume":"91","year":"2008","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/S0925-8388(00)01409-2","article-title":"Phase equilibria and diffusion paths in the Ti-Al-O-N system","volume":"317\u2013318","author":"Seifert","year":"2001","journal-title":"J. Alloys Compd."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"450","DOI":"10.1364\/JOSAB.29.000450","article-title":"Thermal radiation transmission and reflection properties of ceramic 3D photonic crystals","volume":"29","author":"Lee","year":"2012","journal-title":"J. Opt. Soc. Am. 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