Epitaxial thin films Epitaxially grown thin films of LAO can serve various purposes for
correlated electrons heterostructures and devices. LAO is sometimes used as an epitaxial insulator between two conductive layers. Epitaxial LAO films can be grown by several methods, most commonly by
pulsed laser deposition (PLD) and
molecular beam epitaxy (MBE). formed at
LAO-STO interfaces LAO-STO interfaces The most important and common use for epitaxial LAO is at the
lanthanum aluminate-strontium titanate interface. In 2004, it was discovered that when 4 or more unit cells of LAO are
epitaxially grown on
strontium titanate (SrTiO3, STO), a conductive 2-dimensional layer is formed at their interface. Individually, LaAlO3 and SrTiO3 are non-magnetic
insulators, yet LaAlO3/SrTiO3 interfaces exhibit
electrical conductivity,
ferromagnetism, large negative in-plane
magnetoresistance, and giant persistent
photoconductivity. The study of how these properties emerge at the LaAlO3/SrTiO3 interface is a growing area of research in
condensed matter physics.
Substrates Single crystals of lanthanum aluminate are commercially available as a substrate for the
epitaxial growth of perovskites, and particularly for
cuprate superconductors.
Non-epitaxial thin films Thin films of lanthanum aluminate were considered as candidate materials for
high-κ dielectrics in the early-mid 2000s. Despite their attractive
relative dielectric constant of ~25, they were not stable enough in contact with
silicon at the relevant temperatures (~1000 °C). ==See also==