Synthesis, dielectric properties of Bi2/3Cu3Ti4O12 ceramics by the sol–gel method

Synthesis, dielectric properties, and influences oxygen vacancies have on electrical properties of Na1/2Bi1/2Cu3Ti4O12 ceramics prepared by a urea combustion method

“…A high-temperature e 0 peak of the NBCTO-1 sample was observed. This is similar to those observed in NBCTO [24,36], Na 0.5-La 0.5 Cu 3 Ti 4 O 12 [20], and Bi 2/3 Cu 3 Ti 4 O 12 [25] ceramics. The e 0 peak shifted to a higher temperature range after annealing the sample in an O 2 atmosphere.…”

“…The e 0 peak shifted to a higher temperature range after annealing the sample in an O 2 atmosphere. The effect of annealing in an O 2 atmosphere on the temperature dependence of e 0 is similar to that observed in Bi 2/3 Cu 3 Ti 4 O 12 ceramics [25].…”

“…Filling oxygen vacancies may result in changes in the dielectric properties. Thus, it is clearly demonstrated that the oxygen 25 vacancy concentration affects e 0 and tand values of NBCTO ceramics. It is notable that e 0 of NBCTO ceramics decreased as the mean grain size increased.…”

“…CCTO exhibited very high dielectric permittivity (e 0 & 10 3 -10 5 ), depending on several factors including sintering time and temperature [3][4][5][6], electrode material [7,8], annealing treatment [9,10], stoichiometry of Ca, Ti, and Cu [1,11,12], and preparation method to produce CCTO powder [13,14]. Giant dielectric properties of related oxides in the family of ACu 3 Ti 4 O 12 compounds, where A = Bi 2/3 , La 2/3 , Y 2/3 , Na 1/2 Bi 1/2 , Na 1/2 La 1/2 , Na 1/2 Y 1/2 , and Na 1/3 Ca 1/3 Bi 1/3 , have also been observed [15][16][17][18][19][20][21][22][23][24][25][26][27]. Generally, CCTO and ACu 3 Ti 4 O 12 ceramics are synthesized via a solid-state reaction (SSR) method [15-18, 23, 26].…”

“…Although there have been an increasing number of reports about chemical preparation of ACu 3 Ti 4 O 12 ceramics, a single phase of the calcined powders was not successfully obtained [20,22,24,25,[29][30][31]. It is useful to develop a new method to produce a pure phase of ACu 3 Ti 4 O 12 powders and to increase the number of design options and to support a variety of applications in the future.…”