Dielectric properties of La1.75Ba0.25NiO4 ceramics prepared by spark plasma sintering

Giant dielectric constant in Nd2NiO4+δ ceramics obtained by spark plasma sintering

“…The sharp decrease of the vacuum in the chamber indicates some gases emit from the sample. The same sintering behavior has been observed in the La 1.75 Ba 0.25 NiO 4 ceramics, and this peak should be attributed to the emission of the interstitial oxygen, which has come from the air during the calcining process as pointed by the previous work [14]. Although the oxygen in air may infiltrate into the lattice to form interstitials again during the post-annealing process as found by Takeda et al [15], the content of excess oxygen in the spark plasma sintered sample is lower than that in conventional solid-state sintered sample.…”

Giant dielectric permittivity and electronic structure in (Al+Sb)co-doped TiO2 ceramics

“…The examples of giant-dielectric materials are CaCu 3 Ti 4 O 12 and related compounds [1][2][3][4][5][6][7][8], CuO [9], Ln 2Àx Sr x NiO 4 (Ln = Nd, La, Sm) [10][11][12][13], (M,N)-doped NiO systems (M = Li, Na, K and N = Ti, Al, Si, Ta) [14][15][16][17], AFe 1/2 B 1/2 O 3 (A = Ba, Sr, Ca; B = Nb, Ta, Sb) [18,19], and LuFe 2 O 4 [20] ceramics. Unfortunately, tand values of these materials are still larger than 0.04 at 1 kHz which is the standard value for capacitor applications.…”

Structural, magnetic and dielectric properties of La2−xCaxNiO4+δ (x=0, 0.1, 0.2, 0.3)

“…La 2 NiO 4+ı is another member of K 2 NiF 4 family and therefore it is meaningful to study the dielectric properties of modified La 2 NiO 4+ı system. Some research groups have already studied Sr doped La 2 NiO 4+ı [15][16][17], Ba doped La 2 NiO 4+ı [18] and found colossal dielectric behavior. But the origin of giant dielectric constant is still disputable: Park et al [15] and Liu et al [16] ascribed the origin to "charge glassiness" or polaron hopping.…”