Brillouin scattering from spin waves in sputtered Co-Zr films

Thermally excited spin waves in thin Co91-Zr9 sputtered films have been studied at room temperature by Brillouin scattering in external magnetic fields of up to 3.5 kOe. In order to precisely determine the g factor and the surface exchange constant, we extensively studied the Damon--Eshbach mode in a 1-μm-thick film. From the slope of the surface magnon frequency in an external magnetic field, the g factor of 2.17+-0.04 is determined. The surface exchange stiffness constant D/sub s/ has been determined by examining the surface wave-vector dependence on the surface magnon frequency. We obtained a value of D/sub s/ =6.9+-2.0 x 10/sup -9/ Oe cm2. The best way to determine the bulk stiffness constant is to observe the standing spin waves excited in a thin film whose thickness is less than 200 nm. We could observe scattering from the standing spin waves of up to a third order in a film of 85+-5 nm thick. The bulk exchange stiffness constant D/sub b/ of 2.2+-0.4 x 10/sup -9/ Oe cm2 is obtained from the external field dependence of the standing spin-wave frequencies