Sub-harmonic excitation of a planar magneto-mechanical system by means of giant magnetostrictive thin films

In the present paper, we report the first results concerning the studies on non-linear actuation of cantilevers using giant magneto-strictive thin fil ms in the vicinity of the spin reorientation transition (SRT). Bimorph cent imetre beams (24 x 5 mm(2)) were designed using 160 mu m thick glass, and 0 .4 mu m thick multilayer TbFe/Fe films deposited via RF sputtering, using s everal sputtering conditions. Magnetic characteristics of the thin films sh ow the existence of a SRT. Dynamic magneto-elastic excitations were studied experimentally on the few eigen resonance modes of the cantilevers. Sub-ha rmonic excitation at half or one third of the frequency of an eigen resonan ce mode has been achieved near the SRT and the efficiency is as good as for eigen frequency excitation. Comparison between theory and experimental res ults is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.