Comparative studies of pure, Sr-doped, Ni-doped and co-doped CaCu3Ti4O12 ceramics: Enhancement of dielectric properties

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.…”

“…The normal Raman-active peaks at ≈447 cm −1 (A 1g ), ≈513 cm −1 (A 2g ), and ≈575 cm −1 (F 3g ) in (Li + , F − ) co-doped CCTO ceramics were observed, which are assigned to TiO 6 clusters, confirming the crystalline structure with a space group Im-3 structure. 7,34,36 The rotation of the TiO 6 octahedron is correlated to the first two peaks (A g mode), while the Ti-O-Ti anti-stretching vibration is associated with the last peak (F g mode). 7,37 The morphologies of the CCTO and (Li + , F − ) co-doped CCTO ceramics are illustrated in Figure 2.…”

“…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.…”

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

“…Rhouma et al . synthetized Ca 1−x Sr x Cu 3−y Ni y Ti 4 O 12 for ( x and y =0 or 0.1), they found that Sr and Ni substitution leads to a ceramic densification and cubic grain form.…”

“…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.…”