Magnetic Field Effect on Magnetic and Electrical Properties of ${\hbox{Mn}}_{2\hbox{-}{\rm x}}{\hbox{Cu}}_{\rm x}{\hbox{Sb}}$

In order to investigate the magnetic and the electrical properties of Mn
_2-x
Cu
_x
Sb (x =0.06, 0.10, and 0.15), the magnetization and the electrical resistivity measurements were carried out in the temperature range from 10 K to 300 K under magnetic fields up to μ
₀
H=5 T. The Curie temperature T
_C
of Mn
_1.94
Cu
_0.06
Sb was determined to be 517 K. Mn
_1.94
Cu
_0.06
Sb showed a first-order magnetic transition from a ferrimagnetic (FRI) to an antiferromagnetic (AFM) phase at T
_t
= 117 K with a thermal hysteresis of approximately 20 K. The low-field magnetic data of Mn
_1.94
Cu
_0.06
Sb also showed an anomaly at 207 K, indicating a spin reorientation. With increasing x, T
_t
increases to 154 K (x = 0.15), whereas T
_C
is almost constant for 0.06 ≤ x ≤ 0.15. The electrical resistivity changes abruptly by 25%-36% at T
_t
. By applying a magnetic field of μ
₀
H=5 T, T
_t
decreases and the width of the hysteresis increases. In addition, we confirmed that the value of the magnetization at low temperatures below Tt depends on the cooling process for a magnetic field.