Low temperature synthesis and magneto-electrical studies in Nd1-xPbxMnO3 system

The system Nd1-xPbxMnO3 with x <= 0.50 has been synthesized by citrate-gel route. All these samples have shown single phase structure with cubic symmetry. Magnetic and electrical behavior has been studied in the temperature range 4-300 K. The temperature dependent resistivity data shows that metal-semiconductor transitions occurs at temperature T-P similar to 166, 174 and 182 K for x = 0.30, 0.40 and 0.50 respectively. Under the field of 1 T, this transition shifts to higher temperature. These samples have shown maximum MR upto 40% under the field of 1 T at temperature lower than TP. These results are supported by magnetic measurements over the observed temperature range. Resistivity data above TP has been found to fit well with T-n where n = -1/4 for x = 0.30 and n = -1/2 for x = 0.50 which is attributed to the variable range hopping of small polarons. (c) 2005 Springer Science + Business Media, Inc.