Synthesis and phase transition of the orthorhombic BaGd2Mn2O7 phase

Phase transition of BaNd2Mn2O7

“…According to their results, these compounds fundamentally crystallize into a body centered tetragonal structure with the Sr 3 Ti 2 O 7 -type for Ln = Pr-Gd but there is another phase with an orthorhombic distortion for Ln = Nd, Sm and Eu when these compounds were prepared in N 2 atmosphere. The existence of another type of orthorhombic phase for Ln = Tb [3] and Gd [4] are known. A clear difference between these two orthorhombic phases is seen in the X-ray powder diffraction patterns [5].…”

In situ Transmission Electron Microscopy Observation of Multiple Phase Transition in BaGd2Mn2O7

“…Deschizeaux–Cheruy and Joubert were the first to synthesize these manganites (Ln=Nd–Gd) in a N 2 atmosphere 2 . After that, many phases were reported for the oxides, depending on the synthesis or annealing conditions 3–12 . High‐temperature X‐ray diffraction (XRD) analysis, and electrical conductivity and thermal analyses, 3,13,14 revealed phase transitions for the Sm, Eu, Gd, Nd, and Tb compounds, which undergo a transition from orthorhombic to tetragonal on heating.…”

Structural determination of a new phase of monoclinic BaTb2Mn2O7

“…According to their results, these compounds fundamentally crystallize into a body centered tetragonal structure with the Sr 3 Ti 2 O 7 type for Ln = Pr-Gd, but there is another phase with an orthorhombic distortion for Ln = Eu and other rare earths when these compounds were prepared in N 2 atmosphere. The present authors reported the existence of another type of orthorhombic phase for Ln = Tb [3] and Gd [4]. There is clear differences between these two kinds of orthorhombic phases in the X-ray powder diffraction patterns [5]: The main peak in a compound for Ln = Eu, Sm, or Nd is a single peak and the second one splits into double peaks, while the reverse situation occurs in BaTb 2 Mn 2 O 7 and BaGd 2 Mn 2 O 7 .…”