{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T05:27:50Z","timestamp":1767158870843,"version":"3.48.0"},"reference-count":41,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,29]],"date-time":"2025-12-29T00:00:00Z","timestamp":1766966400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FCT\u2013Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["UID\/00285\/2025"],"award-info":[{"award-number":["UID\/00285\/2025"]}]},{"name":"FCT\u2013Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["LA\/P\/0112\/2020"],"award-info":[{"award-number":["LA\/P\/0112\/2020"]}]},{"name":"FCT","award":["LA\/P\/0037\/2020"],"award-info":[{"award-number":["LA\/P\/0037\/2020"]}]},{"name":"FCT","award":["UIDP\/50025\/2020"],"award-info":[{"award-number":["UIDP\/50025\/2020"]}]},{"name":"FCT","award":["UIDB\/50025\/2020"],"award-info":[{"award-number":["UIDB\/50025\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>High-performance dielectric materials that can be processed at ultra-low temperatures are essential for next-generation LTCC technologies and compact RF\u2013microwave components. In this work, a multicomponent Bi\u2013Fe\u2013Nb oxide system was synthesized using a modified citrate sol\u2013gel method and thermally treated at only 400 \u00b0C to investigate its structural evolution and dielectric behavior. XRD and Raman analysis revealed the coexistence of a well-crystallized BiOCl phase embedded within a partially amorphous Bi\u2013Fe\u2013Nb\u2013O matrix. SEM and EDS mapping confirmed the presence of two distinct microstructural regions, reflecting differences in local composition and crystallization kinetics. Microwave measurements at 2.7 and 5.0 GHz showed low dielectric losses and a stable dielectric response. Impedance spectroscopy in the RF range revealed strong Maxwell\u2013Wagner polarization at low frequencies and thermally activated relaxation evidenced by the temperature shift in the modulus and impedance peaks. Arrhenius analysis of the relaxation frequencies yielded similar activation energies from both modulus and impedance formalisms, indicating a single underlying relaxation mechanism. Equivalent-circuit fitting confirmed non-Debye behavior, with nearly temperature-independent capacitance and decreasing resistance consistent with thermally activated conduction. These results demonstrate that the Bi\u2013Fe\u2013Nb system exhibits promising dielectric stability and functional behavior even when processed at exceptionally low temperatures.<\/jats:p>","DOI":"10.3390\/nano16010046","type":"journal-article","created":{"date-parts":[[2025,12,29]],"date-time":"2025-12-29T08:47:27Z","timestamp":1766998047000},"page":"46","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Bismuth-Based Ceramic Processed at Ultra-Low-Temperature for Dielectric Applications"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2217-4584","authenticated-orcid":false,"given":"Susana","family":"Devesa","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, CEMMPRE, ARISE, University of Coimbra, Rua Lu\u00eds Reis Santos, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4084-5764","authenticated-orcid":false,"given":"S\u00edlvia Soreto","family":"Teixeira","sequence":"additional","affiliation":[{"name":"i3N and Department of Physics, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6858-9507","authenticated-orcid":false,"given":"Manuel Pedro","family":"Gra\u00e7a","sequence":"additional","affiliation":[{"name":"i3N and Department of Physics, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7666-4741","authenticated-orcid":false,"given":"Lu\u00eds Cadillon","family":"Costa","sequence":"additional","affiliation":[{"name":"i3N and Department of Physics, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.cossms.2016.02.004","article-title":"Low temperature co-fired ceramics with ultra-low sintering temperature: A review","volume":"20","author":"Sebastian","year":"2016","journal-title":"Curr. 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