“…This is because of their potential applications in various electronic fields such as the charge storage capacitors. [9,10] These studies have resulted in the discovery of a large variety of GDC materials, mostly perovskite oxides, i.e., CuO, [11,12] [AC 3 ](B 4 )O 12 (where A = Ca, Cd, Sr, Na or Th; B = Ti; and C = Cu 2+ or Mn 3+ ), [1,[13][14][15][16][17][18][19]29] (M, N)doped NiO (where M = Li, Na, K, and N = Ti, Al, Si, Ta), [20,21] A(Fe 1/2 B 1/2 )O 3 (where A = Ba, Sr, Ca and B = Nb, Ta, Sb), [22,23] and BaTi 1−x (Ni 1/2 W 1/2 ) x O 3 . [24] Nevertheless, CaCu 3 Ti 4 O 12 (CCTO) is still the most studied material because of its special properties: room temperature dielectric constant value, ε of ∼ 10 3 -10 4 that is independent of temperature and frequency over a wide range.…”