The crystal structure of RESrGaCuO sub 5 (RE: La, Pr, Nd), a gallate-cuprate with strong structural similarities to superconducting cuprates

Journal Article · Sat Aug 01 04:00:00 EDT 1992 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1016/0022-4596(92)90326-Q· OSTI ID:6957701

Roth, G; Adelmann, P; Massing, S ^[1]; Knitter, R ^[2]; Wolf, T ^[3]

---

1. INFP, Karlsruhe (Germany)
2. IMF, Karlsruhe (Germany)
3. ITP, Karlsruhe (Germany)

The crystal structure and some basic properties of RESrGaCuO{sub 5}(RE: La, Pr, Nd, space group Ima2, z = 4, a = 16.277(1) {angstrom}, b = 5.5191(3) {angstrom}, c = 5.3342(3) {angstrom} for RE = Nd) has been studied by powder and single-crystal X-ray methods, electrical resistivity and magnetic susceptibility measurements, DSC, TG, and optical microscopy. The structure consists of almost planar nets of distorted corner sharing Cu-O{sub 6} octahedra connected along the longest axis via Ga-O{sub 4} tetrahedral chains with RE and Sr ions filling the large voids between planes and chains. It is isotypic to the structure of the mineral Brownmillerite (Ca{sub 2}(Al,Fe){sub 2}O{sub 5}). Together with its recently described double Cu-O{sub n} layer counterpart RESr{sub 2}GaCu{sub 2}O{sub 7} it forms a homologous series of new gallate-cuprates which closely resemble the corresponding Ga-free superconducting cuprates with single and double Cu-O{sub n} layers. Stoichiometric RESrGaCuO{sub 5} has a fixed oxygen content and is semiconducting with a strong anisotropy of the optical absorption, indicating a pronounced 2-dimensional character of the electronic properties. P-doping of these materials by partial substitution of RE by additional Sr has not been successful up to now.

• OSTI ID: 6957701
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 99:2; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALINE EARTH METAL COMPOUNDS
CALORIMETRY
CHALCOGENIDES
CHEMICAL ANALYSIS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXPERIMENTAL DATA
GALLIUM COMPOUNDS
GALLIUM OXIDES
GRAVIMETRIC ANALYSIS
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LATTICE PARAMETERS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MATERIALS
MICROSCOPY
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NUMERICAL DATA
OPTICAL MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
QUANTITATIVE CHEMICAL ANALYSIS
RARE EARTH COMPOUNDS
SCATTERING
SEMICONDUCTOR MATERIALS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION