Lecture Gervasi Herranz
|22 May 2008||FWN-Building 5118.-152, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Dr. Gervasi Herranz|
|Affiliation:||Institute of Materials Science of Barcelona|
|Title:||Interfaces and physical properties of oxides|
|Date:||Thu May 22, 2008|
|Telephone:||+31 50 363 4565|
Perovskite oxides exhibit a large spectrum of physical functionalities which are appealing for applications. Their properties can be modified in different ways, e.g., by applying strain or by changing the chemical composition. These effects are particularly strong at hetereointerfaces between two materials with dissimilar structural and electronic properties. Here we present investigations on the interface effects on the physical properties of two paradigmatic perovskite oxides: SrTiO3 (STO) and La2/3Ca1/3MnO3 (LCMO).
STO undergoes an insulator-to-metal transition (IMT) upon doping. Here we show that, in some circumstances, structural or electronic rearrangements at the interface between STO and other oxides lead also to an IMT, and that one can harness these effects to confine high-mobility electrons. This confined conduction can be used prospectively to inject spin-polarized currents. LCMO is a half-metallic manganite and its expected full spin-polarization makes it appealing as electrode in tunnel junctions. However, electronic phase separation occurs near interface with the tunnel barrier. We show that these phenomena are dependent not only on the type of interface, but also on the crystal orientation. We discuss the relative relevance of strain and electronic distributions across the interfaces.
|Last modified:||22 October 2012 2.30 p.m.|