Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air

Journal Article · Thu Apr 01 00:00:00 EST 1999 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1998.8123· OSTI ID:349925

Brown, F; Flores, M J.R.; Kimizuka, N ^[1]; Michiue, Yuichi; Onoda, Mitsuko; Mohri, Takahiko; Nakamura, Masaki ^[2]; Ishizawa, Nobuo ^[3]

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1. Univ. de Sonora, Hermosillo (Mexico). Centro de Investigciones en Polimeros y Materiales
2. National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)
3. Tokyo Inst. of Tech., Yokohama (Japan). Research Lab. of Engineering Materials

Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air are determined by means of a classic quenching method. There exist In{sub 2}TiO{sub 5}, Fe{sub 2}TiO{sub 5} having a pseudo-Brookite-type phase and a new phase, In{sub 3}Ti{sub 2}FeO{sub 10} having a solid solution range from In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 4:6:1 to In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 0.384:0.464:0.152 (mole ratio) on the line InFeO{sub 3}-In{sub 2}Ti{sub 2}O{sub 7}. The crystal structures of In{sub 3}Ti{sub 2}FeO{sub 10} are pyrochlore related with a{sub m} = 5.9171 (5) {angstrom}, b{sub m} = 3.3696 (3) {angstrom}, c{sub m} = 6.3885 (6) {angstrom}, and {beta} = 108.02 (1){degree} in a monoclinic crystal system at 1100 C, and a{sub 0} = 5.9089 (5) {angstrom}, b{sub 0} = 3.3679 (3) {angstrom}, and c{sub 0} = 12.130 (1) {angstrom} in an orthorhombic system at 1200 C. The relationship between the lattice constants of these phases and those of the cubic pyrochlore type are approximately as follows: a{sub m} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub m} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, c{sub m} = {1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({1/4})c{sub p} and {beta} = 109.47{degree} in the monoclinic system, and a{sub 0} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub 0} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, and c{sub 0} = 2/3a{sub p} + ({minus}2/3)b{sub p} + (2/3)c{sub p} in the orthorhombic system, where a{sub p} = b{sub p} = c{sub p} = 9.90 ({angstrom}) are the lattice constants of In{sub 2}Ti{sub 2}O{sub 7} having the cubic pyrochlore type. All solid solutions of In{sub 3}Ti{sub 2}FeO{sub 10} have incommensurate structures with a periodicity of q {times} b{sup *} (q = 0.281--0.356) along the b{sup *} axis and the stoichiometric phase has q = 1/3. In FeO{sub 3} having a layered structure type is unstable between 750 and 1100 C.

• OSTI ID: 349925
• Journal Information: Journal of Solid State Chemistry, Vol. 144, Issue 1; Other Information: PBD: Apr 1999
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PHASE STUDIES
INDIUM OXIDES
TITANIUM OXIDES
IRON OXIDES
TEMPERATURE RANGE 1000-4000 K
X-RAY DIFFRACTION
ELECTRON DIFFRACTION
LATTICE PARAMETERS
PHASE DIAGRAMS
EXPERIMENTAL DATA