Sadin, YounesTaheri-Nassaj, EhsanSchmidt, RainerYourdkhani, AminMyllymäki, SamiJantunen, HeliBarzegar-Barfrooei, Hadi2024-01-222024-01-222024-03-01Younes Sadin, Ehsan Taheri-Nassaj, Rainer Schmidt, Amin Yourdkhani, Sami Myllymäki, Heli Jantunen, Hadi Barzegar -Barfrooei, Novel LiCa(PO3)3 and LiSr(PO3)3 microwave dielectric ceramics, Journal of the European Ceramic Society, Volume 44, Issue 3, 2024, Pages 1617-1626, ISSN 0955-2219, https://doi.org/10.1016/j.jeurceramsoc.2023.10.030.0955-221910.1016/j.jeurceramsoc.2023.10.030https://hdl.handle.net/20.500.14352/94244Está depositada la versión postprint del artículoNovel LiCa(PO3)3 and LiSr(PO3)3 phases were produced by conventional solid-state synthesis and formed into ceramic pellets followed by conventional sintering. The crystal structure, ceramic microstructure, microwave dielectric properties and ac conductivity were investigated. A triclinic space group P1- was obtained from Rietveld refinements, and the lattice vibration modes were determined by Raman spectroscopy. The optimum sintering conditions for LiCa(PO3)3 and LiSr(PO3)3 ceramics were 700 degrees C and 625 degrees C, respectively, both for 10 h. Dense glass-free ceramic microstructures were confirmed by SEM. High relative densities of 94.6 % and 93.8 %, low microwave epsilon r values of 5.85 and 5.62 at 14 GHz, and high quality factors Qxf of 25,200 and 23,450 GHz at 14 GHz were detected. Large negative tau f of -105 and -106 ppm/degrees C were obtained, which are uncommon but highly valuable for offsetting positive tau f values of other systems. Moderate Li+-ion conduction was detected in both compounds by ac impedance spectroscopy.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttps://creativecommons.org/licenses/by-nc-nd/4.0/journal articlehttps://doi.org/10.1016/j.jeurceramsoc.2023.10.030open access538.9Phosphate based dielectric ceramicsLow permittivitySynthesis and sintering processesLTCC applicationFísica del estado sólido2211 Física del Estado Sólido