The current-induced effect on charge-ordered state in the electron-doped Ca1−xLaxMnO3 manganites

The changes of the Young's modulus E and the resistivity ρ under different dc currents for the electron-doped manganites Ca1−xLaxMnO3 (x=0.15, 0.20, 0.25 and 0.30) (CLMO) are investigated by means of in-situ measuring method. For all samples, both values of the relative Young's modulus ΔE and the resistivity ρ are lowered with increasing current at low temperatures. The correlation of these changes in ΔE and ρ is discussed and the resistivity drop induced by the larger current is suggested to originate from the lattice variation. In addition, as the current increases from 10 to 40 mA, the variation of ΔE and ρ becomes smaller with decreasing doping level x, and it is ascribed to the decrease of the charge ordering (CO) component accompanying with the magnetic transition from CE-type to C-type antiferromagnetic (AFM) structure.