The field of

1
Center for Emergent Materials The Ohio State
University
http//cem.osu.edu
New materials for the spintronic toolbox
Highly ordered Sr2CrReO6 films shed light on the
role of spin-orbit coupling

• The field of spintronics has the potential to
  deliver electronic devices that are both faster
  and consume less power than the current devices.
  To realize this potential materials where the
  spins of the mobile electrons are spin polarized
  are needed. The double perovskite Sr2CrReO6 is
  one such promising material. Theoretical studies
  predict that at room temperature it should be a
  metal where 85-100 of the mobile electrons have
  parallel spins. However, experimental studies of
  Sr2CrReO6 have been hampered by the inability of
  researchers to keep Cr and Re atoms from
  occasionally switching places in the crystal.
  These mistakes called antisite defects
  negatively impact the magnetic and electrical
  properties. Researchers at The Ohio State
  University have for the first time succeeded in
  preparing high quality epitaxial films of
  Sr2CrReO6 where the Cr and Re atoms are nearly
  perfectly ordered. Measurements made on these
  films shed new light on the properties of this
  material. The effect of spin-orbit coupling, a
  property associated with compounds containing
  heavy elements (in this case Re), is evident in
  the magnetic properties.
• More surprising is the observation that the
  material is a semiconductor rather than a metal,
  something that had not been anticipated. Not
  only is the ability to grow highly ordered double
  perovskite films a technological breakthrough,
  the unexpected semiconducting behavior is likely
  to stimulate new studies to understand the
  intriguing properties of Sr2CrReO6.

• (a) STEM images of a Sr2CrReO6 (001) film viewed
  along lt110gt direction, showing the high degree of
  Cr/Re ordering. (b) A low-magnification TEM
  image of a Sr2CrReO6 film showing no visible
  dislocation defects.

Co Au Co
Fengyuan Yang, Adam Hauser, Hamish Fraser, Robert
Williams, Manisha Genc, Jennifer Soliz, Patrick
Woodward
An NSF Materials Research Science and Engineering
Center (MRSEC) Supported under Award Number
DMR-0820414