Abstract
We report the growth and magnetic properties of BeTe with Cr doping grown on GaAs(001) substrate at Te-rich condition by solid-source molecular-beam epitaxy. Ferromagnetisms were observed for films with high Cr concentration,
x
. The Curie temperatures
T
C
for
x
=
0.13
and
x
=
0.17
are
175
±
5
K
, while the
T
C
for
x
=
0.27
is
250
±
5
K
. Structural properties were studied by
in situ
reflection high-energy electron diffraction, atomic force microscopy, and x-ray diffraction.
Be
1
−
x
Mn
x
Te
and
Cr
1
−
δ
Te
films were also grown and compared with the Be(Cr)Te films. We show that the ferromagnetic ordering of Be(Cr)Te films can be attributed to precipitations of NiAs
Cr
1
−
δ
Te
.