Studies on Some Titanium-Substituted Fe2MoO4Spinel Oxides

✍ Scribed by A. Roy; J. Ghose

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 254 KB
• Volume: 140
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1998.7846

✦ Synopsis

Electrical resistivity ( ) and thermoelectric power ( ) measurements were carried out in inert atmosphere on Fe 2 Mo 1؊x Ti x O 4 (0.04x41.0) spinel oxides in the temperature ranges 100-600 and 300-600 K, respectively. Thermal activation energy (E a ), carrier concentration (n), activation energy for carrier concentration generation (E n ), and mobility ( ) values have been calculated from resistivity and thermoelectric power data. The results show that conduction in titanium-substituted Fe 2 MoO 4 samples, i.e., Fe 2 Mo 1؊x Ti x O 4 , is carried out through the hopping of charge carriers, and the linear ln ( ) vs 1/T plots show a break at the magnetic phase transition temperature. Progressive substitution of molybdenum by titanium in Fe 2 MoO 4 shows that the ratio of Fe 3؉ /Fe 2؉ decreases and in Fe 2 TiO 4 the ratio is very small. The decrease in the amount of Fe 3؉ with increasing x results in the high resistivity and large lattice parameter of Fe 2 TiO 4 .