Preparation of a new triclinic phase based on a pseudo-fcc subcell in the systems Bi{sub 2}O{sub 3}-Ln{sub 2}O{sub 3} (Ln = Dy, Ho, Er, and Y)
Journal Article
·
· Journal of Solid State Chemistry
- National Institute for Research in Inorganic Materials, Ibaraki (Japan)
A phase equilibrium study of the systems Bi{sub 2}O{sub 3}-Ln{sub 2}O{sub 3} (Ln = lanthanoid including Y) has found a new phase, Bi{sub 1-x}Ln{sub x}O{sub 1.5} (Ln = Dy, Ho, Er, and Y with x = 0.485, 0.485-0.49, 0.49, and 0.475-0.49, respectively). A repetitive long-term solid-state reaction at about 800{degrees}C has generated this low-temperature stable phase. It crystallizes in the triclinic system with a {approx_equal} 8.5 {Angstrom}, b {approx_equal} 10 {Angstrom}, c {approx_equal} 8.5 {Angstrom}, {alpha} {approx_equal} 111{degrees}, {beta} {approx_equal} 106{degrees}, {gamma} {approx_equal} 94{degrees}, and Z = 16. This triclinic structure is based on a pseudo-fcc subcell with a{prime} {approx_equal} 5.4 {Angstrom}. The axial relations between the triclinic supercell and the subcell are a {approx_equal} {radical}5/2a{prime}, b {approx_equal} {radical}7/2a{prime}, and c {approx_equal} {radical}5/2a{prime} {approx_equal} 5.4 {Angstrom}. The axial relations between the triclinic supercell and the subcell are a {approx_equal} {radical}5/1a{prime}, b {approx_equal} {radical}7/2a{prime}, and c {approx_equal} {radical}5/2a{prime}. When heated, the triclinic phase transforms smoothly into the {delta}-Bi{sub 2}O{sub 3} type high-temperature stable phase around 1000{degrees}C; when it is cooled, its rate of transition in the opposite direction is extremely sluggish. This sluggishness seems to be due to the ordering of the cations, Bi{sup 3+} and Ln{sup 3+}, in the triclinic structure.
- OSTI ID:
- 494452
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 124; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
Similar Records
Preparation of a new phase having a cation-ordered C-type rare-earth oxide related structure in the systems Bi{sub 2}O{sub 3}-Ln{sub 2}O{sub 3} (Ln = Sm, Eu, Gd, Tb, and Dy)
Stability, thermal behavior and crystal structure of ion ordered Bi{sub 1-x}Ln{sub x}O{sub 1.5} phases (Ln = Sm-Dy)
Bi{sub 2}La{sub 4}O{sub 9}: A monoclinic phase in the system Bi{sub 2}O{sub 3}-La{sub 2}O{sub 3}
Journal Article
·
Tue Nov 14 23:00:00 EST 1995
· Journal of Solid State Chemistry
·
OSTI ID:430256
Stability, thermal behavior and crystal structure of ion ordered Bi{sub 1-x}Ln{sub x}O{sub 1.5} phases (Ln = Sm-Dy)
Journal Article
·
Fri Feb 14 23:00:00 EST 1997
· Journal of Solid State Chemistry
·
OSTI ID:518426
Bi{sub 2}La{sub 4}O{sub 9}: A monoclinic phase in the system Bi{sub 2}O{sub 3}-La{sub 2}O{sub 3}
Journal Article
·
Mon Jul 01 00:00:00 EDT 1996
· Journal of Solid State Chemistry
·
OSTI ID:494453