Caption: EBSD
image showing the local structure of a thin film. The left half of these
images shows the
preferred direction of the LaSrMnO3-film perpendicular to the
growth direction,
while the right half shows the directions in the plane with the contours
of the individual
nanosheets clearly visible. The distance between two lines in the
pattern is a few
micrometers.
(September 10, 2015) Two-dimensional
crystals are very suitable for creating high-quality magnetic thin films. This
appears from two recent publications written by scientists from the University
of Twente's MESA+ research institute. The researchers show that by growing the
magnetic layers on various 2D crystals, better known as nanosheets, you can
control the preferred direction of the magnetism very locally. In an article
published in Advanced Functional Materials, they present this method to create
magnetic patterns on the micrometer scale. In Angewandte Chemie, they
demonstrate that you can make the nanosheets in less than a minute, while the
synthesis process had been known to be very slow. The magnetic films can be
deployed for many different applications, such as new generations of smartphones.
With pulsed laser deposition (PLD) you can achieve
controlled growth of thin layers of certain materials. Here, a material is
heated rapidly with a powerful laser beam, so that it evaporates and a plasma
is created. This spreads quickly in a vacuum chamber and is deposited on a
substrate where it forms a thin layer. In this way you can control the
thickness of the layer and you can form smooth and thin layers, often with
special properties that are interesting for use in electronics and
electro-mechanics, for example. For such applications, it is however essential
that you can also make patterns in the layered materials. This is not easy,
especially because the substrate needs to be heated to temperatures above 500°
C during the PLD process. Many of the existing methods are therefore not
adapted to existing manufacturing methods for microstructures.