Percolative NiO decorated reduced-graphene oxide with a giant dielectric permittivity

Journal Article · Thu Mar 15 04:00:00 EDT 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.11.024· OSTI ID:22805454

Jammula, Rama Krishna

Highlights: • NiO/r-GO composite exhibited a gaint dielectric permittivity of 3688 at 1 kHz. • NiO/r-GO composite is percolative w.r.t dielectric permittivity and conductivity. • Low threshold percolation is observed. • Increasing r-GO wt% decreased the interfacial resistance consistent with conductivity variation. - Abstract: NiO decorated reduced graphene oxide (r-GO) composites with varying r-GO weight percentages are synthesized using molecular level mixing technique. These composites are found to follow percolation theory with respect to dielectric behavior and conductivity values. A giant permittivity (ε′) value of 3688 was measured at 1 kHz when 2.4 wt% of r-GO was used in preparing NiO/r-GO composite. In comparison to NiO, enhanced permittivity values are recorded in the case of NiO/r-GO composites due to Maxwell-Wagner interfacial polarization between functionalized graphene sheets and NiO particles. It was also observed that ε′ values increased with decreasing NiO grain size up to the percolation threshold value. Moreover, ε′ values are found to be consistent with universal threshold values. Cole–Cole plots’ analysis revealed that the interfaces in the composites are more active than NiO grains.

• OSTI ID: 22805454
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 99; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
DIELECTRIC MATERIALS
GRAIN SIZE
GRAPHENE
KHZ RANGE
NANOCOMPOSITES
NICKEL OXIDES
PERMITTIVITY
POLARIZATION
SHEETS