Effect of bismuth doping on the physical properties of La–Li–Mn–O manganite

The effects of bismuth doping at La site on magnetic, electrical and thermopower properties of LaLiMnO 3 manganites have been investigated. The substitution of Bi ion leads to the weakening of ferromagnetic ordering at low temperature, and Curie temperature ( T C ) decreases with increase in Bi content. Interestingly, a dramatic increase in the magnitude of Seebeck coefficient at low temperature is observed in Bi-doped samples which might find potential application as thermoelectric. The results are attributed to the combined effect of the disorder and antiferromagnetic interaction induced by Bi doping. Both ρ ( T ) and S ( T ) data in the high-temperature region are discussed using small polaron hopping model.