A chemical method for stabilizing a new series of solid solution Pr_1−xCe_xScO₃ (0.0 ≤ x ≤ 1.0) systems

Abstract

A new series of Pr1-xCexScO3 (0.0 ≤x≤ 1.0) compounds was synthesized by a two-step synthesis route, involving a combustion reaction followed by reduction while heating in a low partial pressure of O2, generated by a zirconium sponge that acts as an oxygen getter. For the first time, perovskite solid solution formation was observed in this series in the entire homogeneity range. These compounds were characterized using XRD, Raman spectroscopy and DRUV-visible spectroscopy. Rietveld refinement was carried out on the XRD data to determine unit cell parameters, bond lengths, bond angles along with the tilt angles for ScO6 octahedra. The analyses of the Raman shift were also in agreement with the XRD data. All compounds in this series showed a decreasing trend in the bandgap from 4.74 to 2.91 eV as a function of increasing Ce(3+) concentration.

Investigation of the Nd$_2$O$_3$--Lu$_2$O$_3$--Sc$_2$O$_3$ phase diagram for the preparation of perovskite-type mixed crystals NdLu$_{1-x}$Sc$_x$O$_3$

“…2 shows that the lattice parameters a, b, c depend almost linearly on x and follow Vegard's rule [28]. Comparable behavior was found in the systems CeScO 3 -PrScO 3 [6] and LaScO 3 -LaLuO 3 [5,29].…”

“…Their pseudocubic lattice parameters a pc ≈ 4 Å can be adjusted by an appropriate choice of the RE element occupying the larger cation site of the perovskite structure. Furthermore, mixed crystals between two rare-earth scandates can be grown and allow fine-tuning of a pc [3,4,5,6,7]. Crystals of high quality obtained by the Czochralski technique retain their perovskitic crystal structure during cooling from the melting point down to room temperature.…”