Synthesis and characterization of nonstoichiometric nickel manganite spinels Ni{sub x}Mn{sub 3{minus}x}{open_square}{sub 3{delta}/4}O{sub 4+{delta}}

Journal Article · Fri Jan 31 23:00:00 EST 1997 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(96)00180-8· OSTI ID:455246

Laberty, C; Alphonse, P; Demai, J J; Sarda, C; Rousset, A ^[1]

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1. Univ. Paul Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganiques

The Ni{sub x}Mn{sub 3{minus}x}O{sub 4} spinels have been widely studied, especially in view of their application as thermistor ceramics. Nickel manganites have been prepared by thermal decomposition of mixed oxalates Ni{sub x/3}Mn{sub (3{minus}x)/3}C{sub 2}O{sub 4}{center_dot}nH{sub 2}O in air at 623 K (0 {le} x {le} 1). These oxides are finely divided materials because their BET specific surface areas are close to 100 m{sup 2}/g and the average diameter of their crystallites is about 10 nm. Electron diffraction studies of these compounds show that they crystallize in a spinel-like cubic structure. Thermogravimetric analyses show that these oxides are nonstoichiometric cation deficient spinels Ni{sub x}Mn{sub 3{minus}x}{open_square}{sub 3{delta}/4}O{sub 4+{delta}}. {delta} depends on nickel content and reaches a maximum of 0.9 for x = 0.4.

• OSTI ID: 455246
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 2 Vol. 32; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CRYSTAL STRUCTURE
CUBIC LATTICES
EXPERIMENTAL DATA
MANGANESE OXIDES
NICKEL OXIDES
OXALATES
PARTICLE SIZE
PYROLYSIS
SPINELS
STOICHIOMETRY
SURFACE AREA
SYNTHESIS
TEMPERATURE RANGE 0400-1000 K
THERMISTORS