High-temperature crystal structure and transport properties of the layered cuprates Ln{sub 2}CuO{sub 4}, Ln=Pr, Nd and Sm

Journal Article · Tue Mar 15 04:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.01.035· OSTI ID:21494232

Kaluzhskikh, M S; Kazakov, S M; Mazo, G N ^[1]; Antipov, E V ^[1]; Gippius, A A ^[2]; Fedotov, Yu; Bredikhin, S I ^[3]; Liu, Yi; Svensson, G; Shen, Z ^[4]

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1. Department of Chemistry, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation)
2. Department of Physics, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation)
3. Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow Region (Russian Federation)
4. Department of Materials and Environmental Chemistry, Stockholm University, S-10691 Stockholm (Sweden)

High-temperature crystal structure of the layered cuprates Ln{sub 2}CuO{sub 4}, Ln=Pr, Nd and Sm with tetragonal T'-structure was refined using X-ray powder diffraction data. Substantial anisotropy of the thermal expansion behavior was observed in their crystal structures with thermal expansion coefficients (TEC) along a- and c-axis changing from TEC(a)/TEC(c){approx}1.37 (Pr) to 0.89 (Nd) and 0.72 (Sm). Temperature dependence of the interatomic distances in Ln{sub 2}CuO{sub 4} shows significantly lower expansion rate of the chemical bond between Pr and oxygen atoms (O1) belonging to CuO{sub 2}-planes (TEC(Pr-O1)=11.7 ppm K{sup -1}) in comparison with other cuprates: TEC (Nd-O1)=15.2 ppm K{sup -1} and TEC (Sm-O1)=15.1 ppm K{sup -1}. High-temperature electrical conductivity of Pr{sub 2}CuO{sub 4} is the highest one in the whole studied temperature range (298-1173 K): 0.1-108 S/cm for Pr{sub 2}CuO{sub 4}, 0.07-23 S/cm for Nd{sub 2}CuO{sub 4} and 2x10{sup -4}-9 S/cm for Sm{sub 2}CuO{sub 4}. The trace diffusion coefficient (D{sub T}) of oxygen for Pr{sub 2}CuO{sub 4} determined by isotopic exchange depth profile (IEDP) technique using secondary ion mass spectrometry (SIMS) varies in the range 7.2x10{sup -13} cm{sup 2}/s (973 K) and 3.8x10{sup -10} cm{sup 2}/s (1173 K) which are in between those observed for the manganese and cobalt-based perovskites. -- Graphical abstract: Anomaly anisotropic thermal expansion behavior was observed for Pr{sub 2}CuO{sub 4} in comparison with Ln{sub 2}CuO{sub 4}, Ln=Pr and Nd having tetragonal T'-structure with thermal expansion coefficients (TEC) along a- and c-axis changing from TEC(a)/TEC(c){approx}1.37 (Pr) to 0.89 (Nd) and 0.72 (Sm). It was found that the trace diffusion coefficient (D{sub T}) of oxygen in Pr{sub 2}CuO{sub 4} determined by secondary ion mass spectrometry (SIMS) varies in the range 7.2x10{sup -13} cm{sup 2}/s (973 K) and 3.8x10{sup -10} cm{sup 2}/s (1173 K) which are in between those observed for the manganese and cobalt-based perovskites. Display Omitted Research highlights: {yields} Anisotropic high-temperature thermal expansion behavior of T'-Ln{sub 2}CuO{sub 4}, Ln=Pr, Nd and Sm. {yields} Anomalous expansion behavior of Pr{sub 2}CuO{sub 4} in comparison with Ln{sub 2}CuO{sub 4}, Ln=Nd and Sm. {yields} High-temperature electrical conductivity of Pr{sub 2}CuO{sub 4} is higher in comparison with other T'-Ln{sub 2}CuO{sub 4}. {yields} Values of the oxygen trace diffusion coefficient for Pr{sub 2}CuO{sub 4} are between those reported for the Mn- and Co-based perovskites.

• OSTI ID: 21494232
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 3 Vol. 184; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANISOTROPY
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL BONDS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
CUPRATES
DIFFRACTION
DIFFUSION
DISTANCE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXPANSION
INTERATOMIC DISTANCES
ION MICROPROBE ANALYSIS
ISOTOPIC EXCHANGE
MASS SPECTROSCOPY
MICROANALYSIS
MINERALS
NEODYMIUM COMPOUNDS
NONDESTRUCTIVE ANALYSIS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITES
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SCATTERING
SPECTROSCOPY
TEMPERATURE DEPENDENCE
THERMAL EXPANSION
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION