Development of fundamental components for amplification of magneto-surface-acoustic-waves in highly magnetostrictive metal films by means of electron bunching

摘要

In a magneto-surface-acoustic-wave (MSAW) device, phase velocity is controlled by an external magnetic field. We proposed amplification of MSAW with a hybrid structure of FeB amorphous film / InSb semiconductor thin film / LiNbO_3 substrate, which is expected to compensate the attenuation of MSAW caused by eddy current loss. In the fabricated MSAW device having the FeB amorphous film with low coercivity and high magnetostrictive, the phase retardation of about 600 degree/cm at magnetic fields of +-300 Oe was obtained. The InSb thin film with a mobility of about 3.5X10~3 cm~2/Vs was obtained by using annealing process. The results show possibility of the MSAW amplification.