The substrate dependence of the optical and magneto-optical constants of Mn(x)Sb(1-x) thin films

The structural characteristics and the experimentally measured optical constants (n and k) and magnetooptical constants (Q₁ and Q₂) for RF-sputtered Mn_xSb_1-x films are reported for x in the range 0.13⩽x⩽0.83. Using these constants, prediction is made of the polar Kerr rotation angle, and these values are compared with the experimentally measured values. It is shown that, at close to stoichiometric composition, in the range of 50-at.% and 55-at.% manganese, there is a good agreement between the measured and predicted values of the polar Kerr rotation angle. As the antimony content of the thin films increases, there is an increasing mismatch between measured and predicted values. This may be due to the structural stability of the thin films. The films close to stoichiometric composition are stable and do not oxidize readily, but the antimony-rich films may have slowly oxidized, resulting in a thin film of the oxide on the surface