The results of measurements of the surface magnetic energy at the iron
-silicon interface by means of the standing spin-wave resonance experi
ments, performed at RT. and at frequencies of 17 and 25 GHz, are repor
ted. The samples in the form of thin polycrystalline iron films (10 to
220 nm thick) sandwiched between silicon layers (7.5 nm thick) were p
repared by evaporation in UHV. The surface magnetic energy was found o
f the easy plane type (negative surface anisotropy) with values in the
range -0.4 to -1.8 erg/cm2, its origin is discussed. The theoretical
methods used for the evaluation of the experiment are commented, the p
enetration depth of the spin-wave surface mode is evaluated.