Effects of Cu and Zn co-doping on the electrical properties of Ni0.5Mn2.5O4 NTC ceramics

✍ Scribed by Chunhua Zhao; Biyun Wang; Pinghua Yang; Louis Winnubst; Chusheng Chen

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 569 KB
• Volume: 28
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.06.007

✦ Synopsis

The effects of Cu and Zn co-doping on Ni-Mn-O spinel-structured NTC ceramics were investigated. Dense Cu and Zn co-doped Ni 0.5 Mn 2.5 O 4 spinel-structured ceramics were prepared from mixed oxalate-derived powders. XPS analysis revealed that in the co-doped material Cu x Zn 1.0 Ni 0.5 Mn 1.5-x O 4 , the majority of Cu ions resided at the B-sites due to the almost exclusive occupation of Zn ions at the A-sites, but in the material doped with Cu alone, Cu ions were situated at both A-and B-sites. The co-doped material exhibited a significant decrease in electrical resistivity without much decrease in the thermal constant. In comparison with the material doped with Cu alone, the co-doped material also showed much improved electrical stability upon annealing at 150 • C in air, which is attributed to its stable distribution of cations in the spinel.