caa a22 4500 386401276 CHVBK 20180307112159.0 cr unu---uuuuu 161130e198903 xx s 000 0 eng 10.1017/S0885715600016213 doi S0885715600016213 pii (NATIONALLICENCE)cambridge-10.1017/S0885715600016213 X-Ray Powder Diffraction Characterization of BaR2CuO5 (R=Yttrium and the Lanthanides) and Related Compounds [Elektronische Daten] A series of BaO:RxOy:CuO materials has been prepared where R=Y, La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. They have been characterized by X-ray powder diffraction methods. All BaR2CuO5 phases, commonly referred to as the "green phases”, are orthorhombic with space group Pbnm(62) and are isostructural. These single phase materials could be prepared with most lanthanides, except for La, Ce, Pr, Nd and Tb. Possible reasons for the exceptions are discussed. Both La and Nd tend to form a brown solid solution of Ba2+2xR4-2xCu2-xO10-2x with a tetragonal space group of P4/mbm(127). The major phases found in the Ce, Pr and Tb compositions are the perovskite-related structures BaRO3, and in the Pr case, Ba2PrCu3O6+x as well. The cell parameters of the green phase materials increase progressively from the Lu compound to the Sm compound: a ranges from 7.0506(6) to 7.2754(4) Å, b from 12. 0534(8) to 12. 4029(7) Å, c from 5.6099(5) to 5. 7602(3) Å, and the cell volume from 476.75(6) to 519.78(4) Å3. A correlation of the crystallographic data with the size of the R elements is given. Copyright © Cambridge University Press 1989 Wong-Ng W. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A. Kuchinski M.A. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A. McMurdie H.F. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A. Paretzkin B. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A. Powder Diffraction Cambridge University Press 4/1(1989-03), 2-8 0885-7156 4:1<2 1989 4 PDJ https://doi.org/10.1017/S0885715600016213 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0885715600016213 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wong-Ng W. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A NATIONALLICENCE 700 1- Kuchinski M.A. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A NATIONALLICENCE 700 1- McMurdie H.F. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A NATIONALLICENCE 700 1- Paretzkin B. Ceramics Division, National Institute of Standards and Technology. Gaithersburg, Md. 20899. U.S.A NATIONALLICENCE 773 0- Powder Diffraction Cambridge University Press 4/1(1989-03), 2-8 0885-7156 4:1<2 1989 4 PDJ CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge