Effect of copper on the electrical properties of K1.6(Mg1-yCuy)0.8Ti7.2O16 ceramics

• Published in: Journal of materials science Vol. 33; no. 2; pp. 417 - 421
• Main Authors: KI HYUN YOON, HAN, S, DONG HEON KANG, TAE HEUI KIM
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 1998; Springer Nature B.V
• Subjects: Bonding strength; Bulk density; Ceramics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Copper; Diffusion in solids; Electrical conduction; Electrical properties; Electrical resistivity; Electronic transport in condensed matter; Exact sciences and technology; Grain size; Materials science; Mixed conductivity and conductivity transitions; Physics; Self-diffusion and ionic conduction in nonmetals; Transport properties of condensed matter (nonelectronic); Grain size; Inorganic compounds; Electrical conductivity; Transition element compounds; Ionic conductivity; Ionic conductors; Ceramics; Experimental study; Density; Covalent bonds; Titanium oxides; Multi-element compounds; Ion substitution; Valence; Potassium oxides; Magnesium oxides; Chemical composition; Copper oxides
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1004380015500

The electrical conductivity of the K1.6(Mg1−yCuy)0.8Ti7.2O16 ceramics has been investigated as a function of copper fraction (0≤y≤1). At the calcination temperature of 1000°C, a tetragonal-single phase was obtained for the all compositions. In the specimens sintered at 1100°C for 4 h, the electrical conductivity of the specimens increased with the increasing copper fraction, y. This result can be explained by the weakness of the K–O bonding and the increase of the bulk density and grain size. For the specimens with copper fraction (0≤y<0.8), the electrical conduction was developed mainly by ionic conduction while electronic conduction abruptly occurred at copper fraction y≥0.8. This resulted from the valence transition of copper ions associated with the formation of oxygen vacancies.