Impact of disorder effect on the percolative conductivity in Nd0.5Ca0.5−xSrxMnO3 (0.10 ≤ x ≤ 0.25).

Exploring the disorder effect on percolative conductivity is vital to clarify the correlation between magnetism and electronic transport in manganites. By comparing the electronic transports in Nd 0.5 Ca 0.5− x Sr x MnO 3 samples, we find that the increasing disorder changes the magnetic coupling on Mn-site sublattice and broadens the Curie temperature distribution. The electronic transport agrees well with the percolative model in the low disorder sample whereas an obvious discrepancy occurs in high disorder system. The reason is that the percolative channel forms in short temperature range for low disorder sample but a related broad temperature range for high disorder material. [ABSTRACT FROM AUTHOR]