Abstract
Magnetic field-induced martensitic transformation was realized in
Ni
50
−
x
Co
x
Mn
39
Sb
11
alloys. The partial substitution of Co for Ni has turned the antiferromagnetically aligned Mn moments in the starting material
Ni
50
Mn
39
Sb
11
into a ferromagnetic ordering, raising the magnetization at room temperature from
8
emu
∕
g
for NiMnSb to
∼
110
emu
∕
g
for
Ni
41
Co
9
Mn
39
Sb
11
. In the same quaternary sample, a magnetization difference up to
80
emu
∕
g
was measured across the martensitic transformation, and the transformation temperature
(
T
0
=
259
K
)
could be lowered by
35
K
under a field of
10
T
. Also a magnetoresistance over 70% was observed through this field-induced transformation.