Phase Equilibria and Crystal Chemistry in the Quaternary System Ba‐Sr‐Y‐Cu‐O in Air

Abstract

Studies in the Sr-Y-Cu-0 and Ba-Sr-Y-Cu-0 systems have revealed that Sr will substitute for Ba in (Ba,Sr)2YCu306++ up to about 60%. There are no ternary compounds in the Sr-Y-Cu-0 system equivalent to the three ternary phases in the Ba system. A new binary phase, "Sr14Cu24041" (CuO = 63.158 mol%), was found which forms a solid solution with Y203 to a Sr : Y ratio of approximately 2 : 1. This phase can also incorporate considerable amounts of Ba and Ca and many other large ions. [

Subsolidus phase relations of the SrO–Er2O3–CuO system

“…1. This diagram has the same overall structure as that of the SrO-Ln 2 O 3 -CuO systems with Ln = Y and Yb [3][4][5]14]. There are six three-phase regions, five of which implying SrEr 2 O 4 , and two two-phase regions extending into the ternary diagram.…”

“…Further work is in progress in order to solve this issue. [3][4][5][6][7][8][9][10][11][12][13][14]. The ion size corresponds to trivalent state in VIII-fold coordination.…”

“…However, in order to obtain further information on the crystal chemistry of the alkaline-earth lanthanide cuprates, and possibly discover new superconductors, the phase equilibria of several SrO-Ln x O y -CuO systems have been determined during the last few years. These are the ones involving: Y 2 O 3 [3][4][5], La 2 O 3 [6], Nd 2 O 3 [7], Sm 2 O 3 [8], Eu 2 O 3 [9], Gd 2 O 3 [10], Dy 2 O 3 [11], Ho 2 O 3 [12], Tm 2 O 3 [13] and Yb 2 O 3 [14].…”

Strain effects on point defects and chain-oxygen order-disorder transition in 123 cuprate compounds

“…Secondly, we focus on the effects of strain on Schottky defects and related phenomena for a series of homovalent substitutions at Y and Ba sites of YBa 2 Cu 3 O 7−δ . Although the 123 structure is not stable in the Ca-and Sr-analogs under ambient pressure [23,24,25], partial substitution of Sr on the Ba site has been reported [4,23,26,27,28]. Finally, strain effects on chain-oxygen order-disorder transition of REBa 2 Cu 3 O 7−δ will be investigated.…”

Subsolidus phase relations of the SrO–RE2O3–CuO systems (RE=Tm, Lu and Sc)

“…The published phase diagrams are those involving Y 2 O 3 [1][2][3], La 2 O 3 [4], Nd 2 O 3 [5], Sm 2 O 3 [6], Eu 2 O 3 [7], Gd 2 O 3 [8], Dy 2 O 3 [9], Ho 2 O 3 [10], Er 2 O 3 [11], Tm 2 O 3 [12] and Yb 2 O 3 [13]. These systems were usually investigated in air at 900 • C-950 • C, where the full section is in the solid state.…”