Enhanced electrical properties of La1.9Nd0.1Ti2O7 ceramics.

La_2−xNd_xTi₂O₇ (LNTO) ceramics with enhanced electrical properties have been prepared by traditional solid-state reaction method. The LNTO ceramics maintain a pure monoclinic phase at x ≤ 0.1. At x > 0.1, an orthorhombic phase Nd_0.95TiO₃ appears. Impedance spectra indicates that the substitution of La³⁺ ions by Nd³⁺ ions at A sites generates defects, resulting in the enhanced distortions of TiO₆ octahedrons. The dielectric relaxation activation energy for these defects is 1.2 eV in temperature range T ≥ 650 ℃. The conductance activation energies are 0.3 eV and 1.0 eV for impure ions/thermions and defects/oxygen vacancies, respectively. The contributions of impure ions/thermions and defects/oxygen vacancies have been distinguished through the analysis of both normalized imaginary impedance Z″ and electrical modulus M″. Their impedance relaxation activation energies in normalized Z″ spectra are 1.3 eV and 0.8 eV, respectively. An enhanced piezoelectric coefficient (d₃₃ = 2.8 pC/N) appears in La_1.9Nd_0.1Ti₂O₇ (LNTO-0.1) ceramics. [ABSTRACT FROM AUTHOR]