Extremely reduced loss tangent with retaining ultra high dielectric permittivity in Mg2+-doped La1.9Sr0.1NiO4 ceramics

Advanced humidity sensing properties of CuO ceramics

“…At higher frequencies, ε′ experiences a rapid decline, a phenomenon attributed to dielectric relaxation. In inset (1), the tanδ of CuO is observed to be significantly large (tanδ > 1.0 across the frequency spectrum) relative to other ceramics with high ε′ values, such as Mg–doped La 2- x Sr x NiO 4 , CaCu 3 Ti 4 O 12 , TiO 2 , SrTiO 3 , and NiO–based compounds 4 – 6 , 10 , 17 , 19 – 22 , 28 . Therefore, the practical use of CuO materials in capacitors faces the significant hurdle of reducing the tanδ value to below 0.05.…”

“…Additionally, the non-toxic nature and relative abundance of copper make CuO a more environmentally friendly option compared to other materials with similar properties. Furthermore, the sintering temperature of CuO (approximately 800–980 °C) is much lower than that of other giant dielectric oxides, such as CaCu 3 Ti 4 O 12 at 1050–1100 °C 3 – 5 , 17 , BaTiO 3 at 1400 °C 18 , SrTiO 3 at 1400–1550 °C 6 , La 2- x Sr x NiO 4 at 1350–1400 °C 19 , and NiO at 1400–1610 °C 11 , and TiO 2 –based oxides at 1350–1550 °C 10 , 20 , 21 .…”