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

La2-xNdxTi2O7 (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 Nd0.95TiO3 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 celcius. 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 (d(33) = 2.8 pC/N) appears in La1.9Nd0.1Ti2O7 (LNTO-0.1) ceramics.