{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T03:44:08Z","timestamp":1775706248047,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,11,11]],"date-time":"2019-11-11T00:00:00Z","timestamp":1573430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/CTM\/50011\/2019"],"award-info":[{"award-number":["UID\/CTM\/50011\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["IF\/00602\/2013"],"award-info":[{"award-number":["IF\/00602\/2013"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["IF\/00582\/2015"],"award-info":[{"award-number":["IF\/00582\/2015"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>If piezoelectric micro-devices based on K0.5Na0.5NbO3 (KNN) thin films are to achieve commercialization, it is critical to optimize the films\u2019 performance using low-cost scalable processing conditions. Here, sol\u2013gel derived KNN thin films are deposited using 0.2 and 0.4 M precursor solutions with 5% solely potassium excess and 20% alkali (both potassium and sodium) excess on platinized sapphire substrates with reduced thermal expansion mismatch in relation to KNN. Being then rapid thermal annealed at 750 \u00b0C for 5 min, the films revealed an identical thickness of ~340 nm but different properties. An average grain size of ~100 nm and nearly stoichiometric KNN films are obtained when using 5% potassium excess solution, while 20% alkali excess solutions give the grain size of 500\u2013600 nm and (Na + K)\/Nb ratio of 1.07\u20131.08 in the prepared films. Moreover, the 5% potassium excess solution films have a perovskite structure without clear preferential orientation, whereas a (100) texture appears for 20% alkali excess solutions, being particularly strong for the 0.4 M solution concentration. As a result of the grain size and (100) texturing competition, the highest room-temperature dielectric permittivity and lowest dissipation factor measured in the parallel-plate-capacitor geometry were obtained for KNN films using 0.2 M precursor solutions with 20% alkali excess. These films were also shown to possess more quadratic-like and less coercive local piezoelectric loops, compared to those from 5% potassium excess solution. Furthermore, KNN films with large (100)-textured grains prepared from 0.4 M precursor solution with 20% alkali excess were found to possess superior local piezoresponse attributed to multiscale domain microstructures.<\/jats:p>","DOI":"10.3390\/nano9111600","type":"journal-article","created":{"date-parts":[[2019,11,12]],"date-time":"2019-11-12T04:07:07Z","timestamp":1573531627000},"page":"1600","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Effect of Solution Conditions on the Properties of Sol\u2013Gel Derived Potassium Sodium Niobate Thin Films on Platinized Sapphire Substrates"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0318-9262","authenticated-orcid":false,"given":"Alexander","family":"Tkach","sequence":"first","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Andr\u00e9","family":"Santos","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3891-5209","authenticated-orcid":false,"given":"Sebastian","family":"Zlotnik","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"\u0141ukasiewicz Research Network-Institute of Electronic Materials Technology (ITME), Wolczynska 133, 01-919 Warsaw, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8531-090X","authenticated-orcid":false,"given":"Ricardo","family":"Serrazina","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0885-7127","authenticated-orcid":false,"given":"Olena","family":"Okhay","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"Nanotechnology Research Division, Centre for Mechanical Technology and Automation (TEMA), Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6318-1425","authenticated-orcid":false,"given":"Igor","family":"Bdikin","sequence":"additional","affiliation":[{"name":"Nanotechnology Research Division, Centre for Mechanical Technology and Automation (TEMA), Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Maria Elisabete","family":"Costa","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Paula M.","family":"Vilarinho","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering, CICECO\u2013Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3677","DOI":"10.1111\/jace.12715","article-title":"(K,Na)NbO3-based lead-free piezoceramics: Fundamental aspects, processing technologies, and remaining challenges","volume":"96","author":"Li","year":"2013","journal-title":"J. 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