Tuning the nonlinear current-voltage behavior of CaCu3Ti4O12 ceramics by spark plasma sintering

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

“…The doping of CCTO by Cobalt was studied by Mu et al, [56] Kafi et al [57] and Wang et al [58] Mu et al [56] prepared CaCu 3 Ti 1À x Co x O 12 (x = 0, 0.2, 0.4) ceramics by a conventional solid state reaction. Both X-ray diffraction and energy dispersive X-ray spectroscopy confirmed 3.14 × 10 3 0.161 [42] Spark Plasma Sintering CaCO 3 , TiO 2 , CuO 900°C/5 min 10 5 - [46] Thermobaric Treatment (TBT) CaCO 3 , TiO 2 , CuO CS: 1100°C/24 h TBT:1000°C/10 min (9 GPa) 10 3~1 0 [50] [54] the presence of Cu and Co rich phase at grain boundaries of Co-doped ceramics ( Figure 26). The authors explained that the cobalt can exist in (II) and (III) oxidation states, and can occupy Cu 2 + and Ti 4 + , depending on its oxidation state.…”

“…Lin et al [50] prepared four different ceramic series that were SPS sintered at 900°C for 5 min, 900°C for 20 min, 950°C for 5 min and 950°C for 20 min. Figure 21 shows the microstructure of the different ceramics obtained by SPS.…”

“…Mao et al [53] prepared the Calcium copper titanium oxide (CCTO) ceramics using the following procedure: Ceramics were quenched in air and liquid nitrogen separately after being [50] subjected to sintering in low vacuum and thermobaric treatment (TBT) at 9 GPa and 1000°C for 10 min. The microstructures of the obtained ceramics are shown in Figure 23.…”

Improved dielectric properties of Na1/2Y1/2Cu3Ti4O12 ceramics synthesized by ball-milling and reactive sintering

“…According to this model, the apparent giant dielectric constant arises due to the Maxwell-Wagner polarization effects at internal resistive boundaries such as grain-boundaries and/or domain-boundaries. Recently, a great deal of studies on the effects of doping, powder synthesis and sintering techniques on the dielectric properties of CCTO has been carried out [2][3][4][10][11][12][13][14][15][16]. Most of these studies used the solid state reaction (SSR) technique for the fabrication of ceramics.…”

“…Several studies aimed to replace SSR by lower temperature fabrication process without scarifying the giant dielectric properties of the ceramic. One strategy is to use rapid sintering techniques such as spark plasma sintering (SPS) [11,17] and microwave sintering [18]. Another strategy is to use sol-gel process to prepare the precursor powder with nano-metric size which reduce the calcination and sintering temperature to prepare the dense ceramics [19].…”