He significant semicircular arc corresponding to the GB response will not be observed at 25 C owing towards the substantial total resistance imparted by the insulating regions within the material [10,17,18,51,52]. This concern might be resolved by increasing the temperature in the method to lower the resistance from the GBs. In this study, the upper temperature limit for the instrument was 210 C. As shown in Figure ten, the huge semicircular arc was not observed within the frequency range of 4006 Hz; even at 210 C, only segments with the characteristic semicircular arc had been observed. The total resistance exhibited by the insulating regions inside every single on the LuNTO ceramics is substantial across the whole measured temperature variety. At 210 C, the total resistance exhibited by the LuNTO ceramics is estimated to become greater than ten M m, which can be considerably bigger than the ones exhibited by GD oxides, like CCTO (5 104 m at 200 C) [3,4], V3 /Ta5 co-doped TiO2 (about 1.five M m at 150 C) [10], Al3 /Ta5 co-doped TiO2 (approximately 0.three M m at 200 C) [52], and Gd3 /Nb5 co-doped TiO2 (approximately five 104 m at 150 C) [39]. Inset of Figure 10, the nonzero intercept on the Z plots for each and every on the LuNTO ceramics could be determined, indicating the presence in the Molecules 2021, 26, x FOR PEER Overview semiconducting grains. Hence, the microstructure of the LuNTO ceramics consists15 12 of of insulating regions exhibiting ultra-high resistivity, alongside semiconducting grains. The origin with the GD properties is mostly attributed to the IBLC structure. Nevertheless, it has been suggested, but not however verified, that the EPDD impact may exert an influence on the the GD properties exhibited by the LuNTO ceramics, because the ionic radius from the Lu3 ions GD properties exhibited by the LuNTO ceramics, because the ionic radius of the Lu3 ions is is enough (in comparison to In3) to theoretically induce the formation of EPDDs. enough (in comparison to In3) to theoretically induce the formation of EPDDs.6.005 6.0×40 HzC 210 CoLuNTO-1 LuNTO-2 LuNTO–Z” (.cm)-Z” (.cm)5 four.04.0×100 502.005 two.0x106 Hz40 HzFigure ten. Impedance complicated plane (Z) plots at 200 C for LuNTO-1, LuNTO-2, and LuNTO-3 Figure ten. Impedance complicated plane (Z) plots at 200 for LuNTO1, LuNTO2, and LuNTO3 ceramics; inset shows the nonzero intercept at high frequencies at 30 C. ceramics; inset shows the nonzero intercept at higher frequencies at 30 .The extremely low tan worth of roughly 0.007 exhibited by the LuNTO1 ce ramic at 1 kHz and 30 is attributed for the ultrahigh Propidium Technical Information resistivity exhibited by the internal insulating regions, i.e., the GBs and secondaryphase particles corresponding for the LuN–30 C 30 oC0.0.two.005 two.0xZ’ (.cm)4.005 four.0x6.005 6.0xZ’ (.cm)Molecules 2021, 26,12 ofThe exceptionally low tan worth of around 0.007 exhibited by the LuNTO-1 ceramic at 1 kHz and 30 C is attributed to the ultra-high resistivity exhibited by the internal insulating regions, i.e., the GBs and secondary-phase particles corresponding for the LuNbTiO6 microwave-dielectric phase. The origin with the semiconducting grains is attributed for the Nb5 doping ions, in accordance with Equations (2) and (three). Additionally, the introduction of O vacancies throughout the high-temperature sintering procedure also can be attributed to the presence on the semiconducting grains. The tan values obtained at 1 kHz and 30 C inside the LuNTO-2 and LuNTO-3 ceramics had been bigger than the corresponding values obtained for the LuNTO-1 ceramic. Anle138b Cancer Regardless of this, thei.