Preparation of (Ge $_{1 - {\rm y}}$Pb $_{\rm y}$) $_{1 - {\rm x}}$Mn $_{\rm x}$ Te Thin Films and Their Magnetic Properties

We have prepared various (Ge
_1-y
Pb
_y
)
_1-x
Mn
_x
Te thin films by an ionized cluster beam method on BaF
₂
(111) substrates in order to study the dependences of electrical and magnetic properties on Pb content. Carrier concentration can be controlled from 10
¹⁸
cm
^-3
(y=0.69) to 10
²¹
cm
^-3
(y=0) by Pb content in the films with Mn content x around 0.1. Direct magnetization and magnetotransport measurements were performed and the characteristics of anomalous Hall effect agreed well with the magnetization. The Curie temperature of (Ge
_1-y
Pb
_y
)
_1-x
Mn
_x
Te films decreased with increasing Pb content and ferromagnetic behavior was not observed in magnetotransport measurement at 9 K for the films above y=0.57. An increase of Mn content in (Ge
_1-y
Pb
_y
)
_1-x
Mn
_x
Te films with Pb content y around 0.47 has also been tried. The Curie temperature successfully increased with increasing Mn content till x=0.22.