Structure evolution of Yb substituted PCMO manganites

Abstract In the present investigation, we have made an effort to synthesize and study the structure of Yb substituted Pr0.67-xYbxCa0.33MnO3 (PYCMO) [x = 0.0, 0.09, 0.2, 0.4 and 0.6] manganites. The tolerance factor estimated decreases while the A-site variance increases with an increase in Yb concentration. This gives an insight of the impact of Yb on the structure of the system. Detailed Rietveld analysis of the X-ray diffraction pattern suggests the structural changes to be temperature sensitive and a mixed-phase is found to evolve as the concentration of Yb increases. The parasitic secondary phase has been identified as YbMnO3 (YMO) which crystallizes in hexagonal structure. A strong immiscibility of the orthorhombic and hexagonal phases has been evident from the two-phase Rietveld analysis.