| AVS 57th International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThA |
| Session: | Multifunctional Thin Films and Characterization |
| Presenter: | S.V. Shutthanandan, Pacific Northwest National Laboratory |
| Authors: | S.V. Shutthanandan, Pacific Northwest National Laboratory A. Cohen, Pacific Northwest National Laboratory L. Qiao, Pacific Northwest National Laboratory S.A. Chambers, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
There is a strong and growing interest in complex oxide interfaces because of the wide range of functional properties exhibited. It is well known that the LaAlO3/SrTiO3 (LAO)/(STO) interface exhibits novel electronic conductivity when grown in certain ways. LAO and STO are both band insulators in the bulk, but their interface exhibits n-type electrical conductivity when LAO is grown on TiO2-terminated STO. Rutherford backscattering spectrometry (RBS) was used to determine interface composition in several pulsed laser deposition (PLD) grown LAO/STO samples prepared at leading laboratories. RBS data collected on these samples clearly show that La diffuses deep into the STO substrate. The clear presence of a shoulder between the low energy side of the La peak and the high energy side of the Sr peak suggests La indiffusion, although this shoulder could also be caused by pulse pile up in the detector, straggling, and/or multiple/dual scattering effects. Therefore, RBS data were taken as a function of beam current, incident beam energy, and film thickness to determine if this shoulder is due to these artifacts, or La indiffusion. It was determined that none of the aforementioned artifacts occur, thereby implicating La indiffusion. The presence of substitutional La at Sr sites in the substrate provides a plausible explanation for the observed n-type conductivity, as La is a shallow donor in STO.