Renata Butkute 1Bonifacas Vengalis 1,3Jelena Devenson 1Fiodoras Anisimovas 1Antanas Oginskis 1Alexandra M. Rosa 2

1. Semiconductor Physics Institute, A.Gostauto 11, Vilnius LT-2600, Lithuania
2. University of Lisbon, Lisbon 1749-016, Portugal
3. Vilnius Gediminas Technical University, Sauletekio al. 11, Vilnius LT-2040, Lithuania


In this work, we present the results of growth and investigation of p-n diode structures based on hole-doped lanthanum manganite films. High crystalline quality p-type La2/3A1/3MnO3 (A = Ba, Ca and Ce) thin films were grown heteroepitaxially by pulsed laser deposition and magnetron sputtering onto conductive n-type SrTiO3:Nb (STON) substrates. X-ray diffraction measurements demonstrated perfect crystalline structure of the prepared LBMO and LCaMO films, while traces of CeO2 as a secondary phase have been indicated for the LCeMO films. Resistance versus temperature curves measured for the films with current in-plane geometry were compared to zero field temperature-dependent junction resistance of the p-n structures. The current-voltage characteristics of all the structures exhibited a rectifying behaviour similar to p-n diode with the characteristic barrier voltage in a case of forward bias increasing gradually from about 0.25 V at 300 K to 0.8 V at 78 K. Special attention was focussed on a comparative study of nonlinear current-voltage characteristics, magnetoresistance and photoconductivity of the prepared diode structures. Various heterostructures were annealed at different temperatures under various oxygen pressure conditions. The observed thermal instability of the LCaMO/STON and LCeMO/STON interfaces was associated with formation of high resistance region (tunnel barrier) due to a diffusion of oxygen ions under strong internal electrical field and possible phase separation in the manganite films at the interface.


Related papers
  1. Synthesis and electrical properties of La-Pr-Mn-O thin films and heterostructures
  2. Electrical and magnetic properties of p-n diode structures based on lanthanum manganites and Nb-doped SrTiO3
  3. Magnetoresistance of polycrystalline LCMO films in microwave magnetic field
  4. Electroresistance and magnetoresistance of polycrystalline La0.67Ca0.33MnO3 films
  5. Oxide Heterostructures Based on Fe3O4 Thin Films
  6. Phase separation and microwave response of epitaxial and polycrystalline manganite films
  7. Electroresistance of La-Ca-MnO thin films

Presentation: poster at E-MRS Fall Meeting 2005, Symposium F, by Renata Butkute
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-30 13:36
Revised:   2009-06-07 00:44