  The effect of grain size on structural, magnetic and transport properties in
electron-doped manganites La0.9Te0.1MnO3 has been investigated. All samples
show a rhombohedral structure with the space group at room temperature. It
shows that the Mn-O-Mn bond angle decreases and the Mn-O bond length increases
with the increase of grain size. All samples undergo paramagnetic
(PM)-ferromagnetic (FM) phase transition and an interesting phenomenon that
both magnetization and the Curie temperature decrease with increasing grain
size is observed, which is suggested to mainly originate from the increase of
the Mn-O bond length . Additionally, obviously increases with decreasing grain
size due to the increase of both the height and width of tunneling barriers
with decreasing the grain size. The results indicate that both the intrinsic
colossal magnetoresistance (CMR) and the extrinsic the extrinsic interfacial
magnetoresistance (IMR) can be effectively tuned in La0.9Te0.1MnO3 by changing
grain size.
