Electrostatic potential in manganite-based heterojunctions by electron holography -: art. no. 164102

Electric potentials at the manganite-based heterojunctions, composed of La0.9Sr0.1MnO3 and 0.01 wt % Nb-doped SrTiO3 (p-n junction) and La0.7Ce0.3MnO3 and 0.5 wt % Nb-doped SrTiO3 (n-n junction), have been studied by means of off-axis electron holography. The experimental measurements demonstrate that evident electron diffusion from the n-type SrNbxTi1-xO3 to the manganite films occurs in both p-n and n-n heterojunctions. The p-n heterojunction shows a complex potential change across the interface due to the variation of dielectric constant and electronic structure. In situ cooling experimental measurement on n-n junctions reveals an apparent change of potential along with the ferromagnetic phase transition. (C) 2005 American Institute of Physics.