The crystal structure of neodymium and europium chromate heptahydrate: Synthesis, infrared spectra, and thermal behavior of lanthanoid chromate heptahydrates, (Ln sub 2 (CrO sub 4 ) sub 3 (H sub 2 O) sub 5 )ter dot 2H sub 2 O (Ln=La, Pr, Nd, Sm, Eu, Gd)

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1016/0022-4596(91)90250-L· OSTI ID:7200814

Leppaaaho, J; Valkonen, J ^[1]

---

1. Univ. of Jyvaaskylaa (Finland)

The crystal structures of Nd{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O and Eu{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O were determined by the conventional single-crystal X-ray diffraction technique. In addition, unit cell dimensions were measured for La{sub 2} (CrO{sub 4}){sub 3}{center dot}7H{sub 2}O and Sm{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O. All these compounds are isostructural. Crystals are monoclinic, space group P2{sub 1}/c. For Nd{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O, a=8.052(4){angstrom}, b=19.143(4){angstrom}, c=13.326(6){angstrom}, {beta}=128.15(4){degree}, Z=4, D{sub x}=3.14 Mg{center dot}m{sup {minus}3}, T=296(1); and for Eu{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O, a=7.965(3){angstrom}, b=18.985(4){angstrom}, c=13.185(4){angstrom}, {beta}=128.00(2){degree}, Z=4, D{sub x}=3.29 Mg{center dot}m{sup {minus}3}, T=296(1). Ln atoms are nine-coordinated so that the coordination polyhedron is a tricapped trigonal prism for Ln1 and a monocapped square antiprism for Ln2. Structures form a three-dimensional network. Unit cell dimensions for La{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O are a=8.181(6){angstrom}, b=19.294(6){angstrom}, c=13.436(8){angstrom}, {beta}=128.09(6){degree} and those for Sm{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O are a=7.975(9){angstrom}, b=19.00(1){angstrom}, c=13.18(3){angstrom} and {beta}=127.5(2){degree}. Thermal behavior was investigated and IR spectra were recorded for Ln{sub 2}(CrO{sub 4}){sub 3}{center dot}7H{sub 2}O (Ln=La, Pr, Nd, Sm, Eu, Gd).

• OSTI ID: 7200814
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 92:1; ISSN JSSCB; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
CHROMATES
CHROMIUM COMPOUNDS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
EUROPIUM COMPOUNDS
EXPERIMENTAL DATA
GADOLINIUM COMPOUNDS
GRAVIMETRIC ANALYSIS
HYDRATES
INFORMATION
INFRARED SPECTRA
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
MONOCLINIC LATTICES
NEODYMIUM COMPOUNDS
NUMERICAL DATA
OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SPECTRA
SPECTROSCOPY
SYNTHESIS
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSITION ELEMENT COMPOUNDS