Oxygen Nonstoichiometry, Structures, and Physical Properties of YBaCo2O5+x (0.00≤x≤0.52)

Phase equilibria, crystal structure and oxygen content of intermediate phases in the Y–Ba–Co–O system

“…2 demonstrates XRD patterns of the single phase YBaCo 2 O 5.4 . It was found to be tetragonal with the 3a p  3a p  2a p superstructure (P4/mmm space group, a¼ 11.616(1) Å, c¼ 7.494(1) Å), that is in good agreement with the data presented earlier [2,6].…”

“…The family of LnBaCo 2 O 5 þ δ so-called double perovskites, in particular with Ln ¼Y, was intensively studied during last decade since they exhibit a set of properties such as high values of mixed electronic-ionic conductivity and oxygen mobility [1,2] that allows considering them as the promising cathode materials for the SOFCs [3]. Another representative of the Y-Ba-Co-O system that attracts attention of many researchers is YBaCo 4 O 7 þ δ [4][5][6][7].…”

“…Another representative of the Y-Ba-Co-O system that attracts attention of many researchers is YBaCo 4 O 7 þ δ [4][5][6][7]. Although a number of papers were devoted to the structure and physicochemical properties of LnBaCo 2 O 5 þ δ and YBaCo 4 O 7 þ δ , including the crystal structure and oxygen content [1][2][3][4][5][6][7][8][9][10][11] the information about phase equilibria in the YBa-Co-O system is absent. The only data that can be found has concern the phase formation in the quasibinary Y-Co-O, Y-Ba-O and Ba-Co-O systems.…”

Defect equilibrium in PrBaCo2O5 at elevated temperatures

“…In difference with Ca or Sr substituted cobaltites where doping cations randomly replace lanthanide cations within the entire solubility range, the larger barium cations tend to ordering so that composition Ln 0.5 Ba 0.5 CoO 3 À δ is characterized by alternation of Ln and Ba cations along c-axis [1][2][3][4]. Consequently, the elementary unit parameters a, b and c for Ln 0.5 Ba 0.5 CoO 3 À δ approximately relate with the elementary unit parameter a p for the parent perovskite-like cobaltite as a p , 2a p and 2a p , respectively, while the obtained oxides are called "double perovskite" cobaltites and their chemical formula is usually represented as LnBaCo 2 O 5+δ .…”

Local Lattice Distortion Caused by Short-Range Charge Ordering in Transition Metal Oxides

“…The inequivalent Co sites with the valences of +2 and +3 are alternately arranged in the unit cell. Although the cubic phase of LiMn 2 O 4 , and the tetragonal and intermediate orthorhombic phases of YBaCo 2 O 5 have the transition metal ions with the half-integer valences, their electrical conductivities are non-metallic, [8,[12][13][14][15][16][17] suggesting the short-range charge ordering. Then we have performed the local structural analyses by using PDFs obtained in the cubic phase of LiMn 2 O 4 and the tetragonal phase of YBaCo 2 O 5 to reveal the local lattice distortion caused by the short-range charge ordering.…”