Molecular Beam Epitaxy Growth of Strontium Cobaltite
EMSL Project ID
11099
Abstract
There has been increasing interest in oxygen-deficient perovskite structures for use in solid oxide fuel cells and oxygen separation membranes. Strontium Cobaltite (SrCoO3) typically exists in the perovskite crystal structure; however, if the SrCoO3 is produced in a low-oxygen environment, it can exist in an oxygen-deficient perovskite form or in a brownmillerite form.Another field of growing interest is spintronics. Diluted magnetic semiconductors (DMS) play an important role in the development of spin-based electronic devices. Because of its ferromagnetic nature, Co was used as a dopant in TiO2 to produce a DMS.
Thus, SrCoO3 is of significant interest for several reasons. However, to use SrCoO3 as a DMS, it must be made with very few or, preferably, no defects in the lattice. SrCoO3 is generally produced by bonding ceramic powders in a high-pressure, high-temperature environment. Molecular beam epitaxy (MBE) potentially provides a way to produce SrCoO3 with few defects. The only requirement for MBE is a substrate that encourages epitaxial growth, and choosing a substrate with good lattice matching does this. Strontium Titanite (SrTiO3) was chosen as a substrate to provide good lattice matching and because it has a similar structure?SrTiO3 is also perovskite.
This work proposes to grow several more strontium-cobaltite films to determine the best parameters for growth and to better characterize the growth process for each crystal structure (perovskite and brownmillerite). The intent is to build a set of growth parameters that allows the selection of the crystal structure and/or the properties required for use in spintronics and DMS.
Project Details
Project type
Exploratory Research
Start Date
2005-03-01
End Date
2006-04-10
Status
Closed
Released Data Link
Team
Principal Investigator