Theoretical Study of Spontaneous Polarization Behavior and Density Behavior of Ni-Doped LiMO₃ (M˭Nb or Ta)

Abstract

In this work we have studied by our theoretical approach a density and a spontaneous polarization behavior of the Ni-doped LiMO₃(M˭Ta or Nb), according to the rate of Ni, the calculated values and the curves of the spontaneous polarization Ps and the density show that the mechanism of substitution of Ni in LiMO₃ is described by two vacancy models: the first is [Li_1−5x−3yM_x−y Ni_4y Δ_4x][M]O₃ for %N < 3 and the second one is [Li_1+5x−13yNi_5y−x Δ_{4 (2y−x)}][M_1−(x−y) Ni_(x−y)] O₃ for ${\displaystyle \%Ni\hspace{0.17em}\ge \hspace{0.17em}3}$.

Keywords:

• Spontaneous polarization
• vacancy model
• nickel
• LiNbO₃
• LiTaO₃