LaAlO3 and NdGaO3 thin films of different thicknesses have been grown by pulsed laser deposition on TiO2-terminated SrTiO3 single crystals and investigated by soft X-ray photoemission spectroscopy. The surface sensitivity of the measurements has been tuned by varying photon energy hν and emission angle . In contrast to the core levels of the other elements, the Sr 3d line shows an unexpected splitting for higher surface sensitivity, signaling the presence of a second strontium component. From our quantitative analysis we conclude that during the growth process Sr atoms diffuse away from the substrate and segregate at the surface of the heterostructure, possibly forming strontium oxide.
Observation of strontium segregation in LaAlO3/SrTiO3 and NdGaO3/SrTiO3 oxide heterostructures by X-ray photoemission / Uwe, Treske; Nadine, Heming; Martin, Knupfer; Bernd, Büchner; Andreas, Koitzsch; DI GENNARO, Emiliano; SCOTTI DI UCCIO, Umberto; Fabio Miletto, Granozio; Stefan, Krause. - In: APL MATERIALS. - ISSN 2166-532X. - 2:(2014), p. 012108. [10.1063/1.4861797]
Observation of strontium segregation in LaAlO3/SrTiO3 and NdGaO3/SrTiO3 oxide heterostructures by X-ray photoemission
DI GENNARO, EMILIANO;SCOTTI DI UCCIO, UMBERTO;
2014
Abstract
LaAlO3 and NdGaO3 thin films of different thicknesses have been grown by pulsed laser deposition on TiO2-terminated SrTiO3 single crystals and investigated by soft X-ray photoemission spectroscopy. The surface sensitivity of the measurements has been tuned by varying photon energy hν and emission angle . In contrast to the core levels of the other elements, the Sr 3d line shows an unexpected splitting for higher surface sensitivity, signaling the presence of a second strontium component. From our quantitative analysis we conclude that during the growth process Sr atoms diffuse away from the substrate and segregate at the surface of the heterostructure, possibly forming strontium oxide.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
