Effects of LiF addition on microstructure and dielectric properties of CaCu3Ti4O12 ceramics

Giant dielectric behavior of monovalent cation/anion (Li+, F−) co‐doped CaCu3Ti4O12 ceramics

“…The (Li + , F − ) co‐dopants may play a primary role in the enlarged grain sizes. Such grain growth may be attributed to liquid‐phase sintering behavior, which is usually reported in CCTO ceramics . The low‐temperature eutectic liquid phase for CuO–TiO 2 occurs at approximately 919°C, and the low melting point of LiF (~846°C) is likely the primary source of the liquid phase during sintering.…”

“…Such grain growth may be attributed to liquid-phase sintering behavior, which is usually reported in CCTO ceramics. 10,11,14,33,36,38 The low-temperature eutectic liquid phase for CuO-TiO 2 occurs at approximately 919°C, 10,39 and the low melting point of LiF (~846°C) 40 is likely the primary source of the liquid phase during sintering. During the sintering process, charges diffuse more easily across the liquid phase than in the solid phase, giving rise to fast grain growth in the (Li + , F − ) co-doped CCTO ceramics.…”

“…According to previous reports, doping F − anions onto O 2− sites can play two critical roles: (a) increase the GB resistance due to the enhanced potential barrier height at the GBs and (b) increase the free electrons in the grain interior due to the charge compensation resulting from reducing Ti 4+ → Ti 3+ and/or Cu 2+ → Cu + . On the other hand, it was reported that a dense microstructure was achieved by adding or doping Li + onto the Cu site of CCTO ceramics, hence improving the IBLC microstructure . Although the dielectric properties of CCTO ceramics co‐doped with different cations on different sites of the crystal structure have been widely reported in recent years, there is no report for simultaneous cation and anion co‐doping into the CCTO crystal structure.…”

“…On the other hand, it was reported that a dense microstructure was achieved by adding or doping Li + onto the Cu site of CCTO ceramics, hence improving the IBLC microstructure. 13,33 Although the dielectric properties of CCTO ceramics co-doped with different cations on different sites of the crystal structure have been widely reported in recent years, there is no report for simultaneous cation and anion co-doping into the CCTO crystal structure.…”

From Synthesis to Applications: Copper Calcium Titanate (CCTO) and its Magnetic and Photocatalytic Properties

“…The effect of the codoping with Li + and Al 3 + on the dielectric properties of CCTO was studied by Sun et al [ [105] Bi/Al 1 % mol 4,020 10 À 1 2.29-3.24 [97] Sr/Ni X = 0.1/0.1 44,410 0.07 35.50 [108] Sr/Zn x = 0.05/0.1 29,664 0.049 0.74 [103] La/Zn Zn (5-10 %) 8,102 0.1 3-4 [99] Y 3 + / Zn 4 + 3 mol%/5 mol % 10,196~0.039 1.3-3.5 [106] Sm/Zn x = 0.05/0.1 5,313 0.041~2 [96] Mg/Y x = 0.05/0.05~10 4~0 .013~3.73 [88] Nb 5 + / Al 3 + x = 0.025 4.1 × 10 4 0.058~35.1 [89] Nb 5 + / Al 3 + x = 0.05 2.9 × 10 4 0.045~34.6 [89] Mg/Y x = 0.05/0.05~10 4~0 .013~3.73 [88] Nb 5 + / Al 3 + x = 0.025 4.1 × 10 4 0.058~35.1 [89] Nb 5 + / Al 3 + x = 0.05 2.9 × 10 4 0.045~34.6 [89] Sr/La x = 0.4/0.15~4 × 10 4~0 .05 0.6 [91] Ni 2 + / Zr 4 + x = 0.05/0.1~2 × 10 4 0.026 4.75 [104] LiF 0.5 % 34,994 0.68 2.1 [92] Yb/Mg x = 0.05/0.3~10 4 0.018 2.32 [107] FeNb x = 0.5 8.0 × 10 4~0 .8 1.9 [98] . Copyright 2018 Elsevier.…”