Electrical conductivity and complex impedance analysis of La0.7−xNdxSr0.3Mn0.7Ti0.3O3 (x≤0.30) perovskite

• Published in: Journal of magnetism and magnetic materials 2016-03, Vol.401, p.853-859
• Main Authors: Abassi, Amel, Kallel, Nabil, Kallel, Sami, Khirouni, Kamel, Peña, Octavio
• Format: Article
• Language: English
• Subjects: Ac conductivity; Chemical Sciences; Impedance spectroscopy; Perovskite; Relaxation phenomena
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2015.10.115

Polycrystalline samples La0.7−xNdxSr0.3Mn0.7Ti0.3O3 (x=0.10; 0.20 and 0.30) were prepared by a high-temperature solid-state reaction technique. The X-ray diffraction shows that all the samples crystallize in the orthorhombic structure, Pbnm space group, with presence of a minor unreacted Nd2O3. The electrical response was studied by impedance complex spectroscopy over a broad frequency range (40–100MHz) at room temperature. The values of ac conductivity for all samples were fitted by the Jonscher law σ(ω)=σdc+Aωs. For x=0.10 and 0.20, hopping occurs between neighboring sites, whereas for x=0.30 the hopping process occurs through longer distance. Complex impedance plots exhibit semicircular arcs described by an electrical equivalent circuit, which indicates that the Nd-doped compounds obey a non-Debye relaxation process. •The La0.7−xNdxSr0.3Mn0.7Ti0.3O3 samples crystallize in the orthorhombic structure.•The conductivity decreases with increasing Nd concentration.•The impedance spectra are characterized by the appearance of semicircle arcs.•The distribution function of relaxation time presents a symmetrical shape with respect to the central frequency.