Magneto-Optical Properties of PtMnSb Films Prepared by RF Magnetron Sputtering

PtMnSb Heusler alloy films were prepared by RF magnetron sputtering from mosaic targets. Films with a polar Kerr rotation and a Clb-PtMnSb (111) diffraction peak were obtained on glass substrates at room temperature. The compositions of these films were in the range 19 ⩽ x 32, 35 ⩽ y ⩽ 46 and 28 ⩽ z ⩽ 38 for Pt
_x
Mn
_y
Sb
_z
(x + y + z = 100). During DC bias sputtering, the Sb and Mn contents were selectively decreased by increasing the DC bias voltage. For film deposited at 400°C on a glass substrate, the polar Kerr rotation was found to be 1.18° on the glass side when an external 7 kOe dc magnetic field was applied perpendicularly. SEM observations revealed a columnar microstructure, and a perpendicular component of magnetization was detected using a VSM. However, this component was not strong enough to cancel the demagnetizing field.