Study of conduction mechanism in aluminium and magnesium co-substituted lithium ferrite

• Published in: Journal of materials science 2005-10, Vol.40 (19), p.5223-5232
• Main Authors: PANDYA, M. P, MODI, K. B, JOSHI, H. H
• Format: Article
• Language: English
• Subjects: Aluminium; Aluminum; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity of specific materials; Conductors; Electrical resistivity; Electronic transport in condensed matter; Electronics; Electrotechnical and electronic ceramics; Exact sciences and technology; Ferrites; Lithium ferrite; Magnesium; Materials science; Physics; Substitutes; Technical ceramics; Temperature dependence; Thermoelectricity; Transition-metal compounds
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-005-4416-z

The conduction mechanism in Mg2 + and Al3 + substituted Li0.5Fe2.5O4 with general formula MgxAl2xLi0.5(1 − x)Fe2.5(1 − x)O4 (x = 0.0, 0.2, 0.5, 0.6 and 0.7) has been studied by means of compositional and temperature dependent d.c. resistivity, thermoelectric power and I–V characteristics measurements. It is found that ferrites are electronic conductors. For x = 0.0 and 0.2 conduction is due to holes, while for x = 0.5, 0.6 and 0.7 it is due to electrons. Thermal variation of mobilities and activation energies determined through d.c. resistivity measurements confirm the formation of small polarons. The sample with x = 0.0 exhibits switching phenomena.