Structural characteristics of Sr1−xLaxTi3+δ as a function of oxygen partial pressure at 1400 °C

Abstract

The structural characteristics of Sr1−x Lax TiO3+δ (0≤x≤0.4) at 1400 °C have been investigated as a function of ambient oxygen partial pressure. A modified Rietveld pattern-fitting structure-refinement program [H. M. Rietveld, J. Appl. Crystallogr. 2, 65 (1969)] was used to determine the nature of the distortions of the fundamental perovskite unit cell, the degree of lattice perfection, and the cation vacancy concentrations. Specimens equilibrated in forming gas displayed a linear relation between x, the lattice parameters, and the degree of lattice perfection while those samples annealed in air and oxygen deviated significantly from linearity. A monoclinic distortion of the perovskite structure was seen in the samples at low oxygen partial pressures while a second phase or layer type of distortion appeared in samples with x>0.2 under oxidizing conditions.

Transmission-electron-microscopy study of quasi-epitaxial tungsten-bronze (Sr2.5Ba2.5Nb10O30) thin film on perovskite (SrTiO3) single crystal

“…79-0174). 10,11 It can be seen that the value of c SBN is close to the value of a STO , which means that it is possible for SBN to grow epitaxially on STO substrate. On the other hand, the value of a SBN is much larger than the value of a STO .…”

Local Structure Analysis of Lanthanum-Doped Strontium Titanate by Means of X-Ray Fluorescence Holography

“…This should be understood on the basis of the crystal structure change from x=0 to x=0.05 above T a . The average crystal structures of Sr 1-x La x TiO 3 with x ≤ 0.2 showed that La atoms are substituted for Sr atoms [7]. However, we need to investigate the arrangement of Sr(La) atoms and TiO 6 octahedra around La atoms in the sublattices constructed, respectively, by Sr(La) atoms and Ti atoms above T a [4].…”

Raman and XPS Studies for Ba1-xEuxTiO3 Synthesized by High Pressure and Temperature.

“…,Ln,TiO3, cubic or pseudocubic lattice was reported in Sr1-x ,LnxTiO3 [6]. But for our samples, in addition to cubic and tetragonal phases, two samples with mixed phase of cubic and tetragonal were synthesized, which indicates that high pressure and temperature play an important role in the formation of different structures.…”

“…The structure and properties RTiO3 compounds, adopt the orthorhombic GdFeO3 structure (space group Pbnm) and shown insulating, can be varied by chemical substitution of A2+ for R3+ forming solid solutions of general formula R1-xAxTiO3 (R=Ca, Sr and Ba) [3][4][5][6].…”