Effects of Ion Bombardment on Magnetostrictive Properties of Giant Magnetostrictive Thin Films

Sm27Fe73 films fabricated by a magnetron sputtering were studied with respect to magnetism and plasma physics. A new parameter 'P-i' was proposed to evaluate effects of ion bombardment for a magnetostriction. The P-i is represented as P-i = (i/a).(2m(i)E(i))(1/2), here i is ion flux, a is material flux, m(i) is the ion mass and E-i is the ion energy. The plasma parameter was determined by Langmuir probes. As a result, the inplane magnetic anisotropy was enhanced by increasing of the P-i. Increase of the P-i induced an increase of magnetostrictive susceptibility and a decrease of saturated magnetstriction. This is probably caused by a change of internal stress accompanied with the P-i.