X-RAY, TRANSPORT, MAGNETIC, MOSSBAUER AND CATALYTIC STUDIES OF THE SYSTEM ZN1-XCUXMNFEO4

The system Zn1-x CuxMnFeO4 has been studied with a view to investigating the cation distribution, transport and magnetic properties and to correlate the physical properties of oxidic spinels with their catalytic behaviour in benzyl alcohol decomposition. The system was found to be tetragonal in the range 0.0 less-than-or-equal-to x less-than-or-equal-to 0.2 and cubic in the range 0.4 less-than-or-equal-to x less-than-or-equal-to 1.0. The activation energy values of electronic conduction varied between 56.69 and 13.01 kJ mol-1. Thermoelectric power measurements indicated p-type semiconducting nature for all the compounds up to 600 K. Mossbauer studies indicated the ferrimagnetic nature of compounds with x greater-than-or-equal-to 0.8 while the rest of the compositions indicated quadrupole doublets. Catalytic behaviour of the catalysts prepared was investigated for the decomposition of benzyl alcohol in the temperature range 473-673 K. A good correlation could be established between cation distribution, transport, magnetic nature and catalytic behaviour.