Self-Energy Effects in Manganite Tunneling
|Vladimir M. SVISTUNOV 1, Yurii F. Revenko 1, Mikhail A. Belogolovskii 1, Alexander Y. Gerasimenko 1, Yurii G. Pashkevich 1, Henryk Szymczak , Piotr Przyslupski 2, Ivan Komissarov|
1. National Academy of Sciences of Ukraine, A.Galkin Donetsk Institute for Physics & Technology (DonPTI NASU), Roza Luxemburg 72, Donetsk 83114, Ukraine
Tunneling spectroscopy experiments on ceramic and film LCMO, LSMO, NSMO systems are reported. The electron boson interaction spectral function in a wide energy range has been reconstructed. Besides the known from Raman spectra data phonon features up to 80meV, the experimental curves clearly indicate the presence of bosonic excitations in the region above 100meV. Qualitative changes of tunneling spectra (below and above 100meV) caused by chemical modification of the oxide surface (oxygen ion displacements) after application of high voltages to the junction were revealed. Its effect is the enrichment of manganite surface layers by oxygen. After application of high biases, junction resistances were reduced and the ratio of peaks below and above 100meV was increased. These results are discussed within a scenario involving a Strong Electron-Phonon Interaction, a possible orbital ordering that has been recently predicted(observed in only LaMnO3) and Tunneling Magnetoresistance.
Presentation: poster at E-MRS Fall Meeting 2003, Symposium D, by Vladimir M. SVISTUNOV
See On-line Journal of E-MRS Fall Meeting 2003
Submitted: 2003-05-13 12:26 Revised: 2009-06-08 12:55