Electrochemical intercalation of oxygen in La{sub 2}NiO{sub 4+x}: Phase separation below ambient temperature

Journal Article · Tue Nov 01 04:00:00 EST 1994 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm00047a030· OSTI ID:98752

Yazdi, I; Bhavaraju, S; DiCarlo, J F; Scarfe, D P; Jacobson, A J ^[1]

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1. Univ. of Houston, TX (United States)

Electrochemical intercalation of oxygen in La{sub 2}NiO{sub 4+x} has been investigated by galvanostatic and potential step experiments for 268 K {le} T {le} 295 K in the composition range 0 {le} x {le} 0.14. At room temperature a single-phase region in the composition range (0.06 < x < 0.14) is observed. When the temperature is lowered to 273 K, the electrochemical data show evidence for phase separation into three distinct two-phase regions with compositions centered at x = 0.076, 0.100, and 0.119. Single-phase regions with compositions centered at x = 0.065, 0.087, and 0.112 are observed between the two-phase regions. The kinetics of the phase separation are slow. The results are consistent with recent low-temperature X-ray and neutron diffraction studies of phase separation at specific compositions. 30 refs., 11 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 98752
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 11 Vol. 6; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL PREPARATION
DIFFUSION
LANTHANUM OXIDES
MONOCRYSTALS
OXYGEN ADDITIONS
PHASE TRANSFORMATIONS
STRUCTURAL CHEMICAL ANALYSIS