Simulation of ion transport in layered cuprates La{sub 2{sub -}}{sub x}Sr{sub x}CuO{sub 4-{delta}}

Journal Article · Sat Mar 15 04:00:00 EDT 2008 · Crystallography Reports

DOI:https://doi.org/10.1007/S11445-008-2019-X· OSTI ID:21090604

Savvin, S N; Mazo, G N ^[1]

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1. Moscow State University (Russian Federation)

The processes of oxygen diffusion in La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}} phases have been simulated for the first time by the molecular-dynamics method. Calculations were performed for the temperature range 300-2500 K. The behavior of the radial pair correlation functions, which characterize the degree of order of O1 ions in CuO{sub 2} layers, indicates that O{sup 2-} anions form a weakly correlated subsystem within a CuO{sub 2} layer. To quantitatively confirm the conclusions about the predominantly two-dimensional character of ion transport and different mobilities of O1 and O2 particles in the cuprates under study, the pair oxygen diffusion coefficients in the La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}} lattice were calculated. It is shown that oxygen diffusion occurs through the conventional hopping mechanism mainly in CuO{sub 2} layers; correspondingly, the diffusion coefficient for equatorial ions (O1) exceeds that for apical oxygen anions (O2) by an order of magnitude. The motion of oxygen anions was traced at the microscopic level through analysis of the particle transport trajectories. It has been proven for the first time that diffusion of O1 ions in the ab plane in a nonstoichiometric LaSrCuO{sub 3.61} sample occurs through jumps to the nearest position or along CuO{sub 2} layers; in a more complicated way, it may occur through unoccupied O2 lattice sites.

• OSTI ID: 21090604
• Journal Information: Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 2 Vol. 53; ISSN CYSTE3; ISSN 1063-7745
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHARGED-PARTICLE TRANSPORT
COPPER OXIDES
CUPRATES
DIFFUSION
LANTHANUM COMPOUNDS
LAYERS
MOLECULAR DYNAMICS METHOD
OXYGEN IONS
SIMULATION
STRONTIUM COMPOUNDS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K