Effect of the Cation Size Disorder at the A-Site on the Structural Properties of SrAFeTiO6 Double Perovskites (A = La, Pr or Nd)

In this paper, the cation size disorder effect of the A-site on the structural properties of the SrAFeTiO6 (A = La, Pr or Nd) was investigated. The compounds were synthesized—as the best of our knowledge—for the first time by conventional and precursor method to get crystalline materials. The results obtained from the experimental measurements carried out on new double perovskite materials were presented. The data of X-ray diffraction (XRD), Fourier Transform Infra Red FTIR were measured at room temperature. From the X-ray diffraction, and by means of standard Rietiveld method, all the samples have the same structure (orthorhombic) with Pnma space group. The difference in the tolerance factor is clearly noticed and refers to the cation size disorder at the A-sites. The Fourier Transform Infra Red FTIR measurement has been done; the results of it confirm the double perovskite structure and the difference between the samples were noticed. The tolerance factors for the samples altered from SrLaFeTiO6 up to SrNdFeTiO6 and this difference return to ionic radius and cation size effect.