Synthesis and Investigation of Physical Properties in Ruddlesden-Popper Perovskite Compounds

Abstract

The search for the possibility of oxides possessing distinctive properties of superconductivity, ionic conductivity, and many insulating properties of great importance in microelectronics , wired and wireless communications is increasing. One of the most important of these oxides is perovskite oxides and compounds derived from layered perovskite structure called the Ruddlesden and Popper series New oxides from the Ruddlesden and Popper series (An + 1 Bn O3n + 1) were synthesized, prepared using the ceramic and sol-gel methods. The physical properties of these oxides and the effect of partial cobalt substitution in the crystalline network with the copper transition element were studied and ,at the same time, the partial substitution of strontium with gadolinium (a rare earth element) was studied. The results of X-ray diffraction shows that the prepared oxides crystallize according to the tetragonal crystalline structure within the I4 / mmm space group at n = 1 ,a decrease of the lattice constants a and b ,an increase in c, and thus an increase in cell unit size when partial substitution of cobalt with copper and strontium with gadolinium where the oxygen atoms are settled in the vacant sites when moving from 2+ oxidation states of Strontium to 3+ oxidation states of Gadolinium andw hen adding the copper element, the resistance decreased, the conductivity increased, and this is due to the movement of oxygen. In contrast, the resistance increased clearly, and the conductivity decreased when the element Gadolinium was introduced due to the movement of the electrons.