Magnetostrictive properties of Ar ion irradiated R Fe(R: Tb, Sm) thin films were studied with respect to residual stress. Film samples were prepared by a magnetron sputtering. The film composition was Tb 36 Fe 64 and Sm 27 Fe 73 with amorphous structures. After the deposition, film samples were irradiated by Ar ions with an energy of 10 keV and a current density of 27 80× 10 -2 A/m 2 up to 1×10 22 ions/m 2 . Magnetostrictive susceptibility of the Tb 36 Fe 64 film decreased with increasing ion current density by 55×10 -2 A/m 2 , however, improved with high current density above 70×10 -2 A/m 2 . Magnetostrictive susceptibility of Sm 27 Fe 73 increased with increasing ion current density up to 55×10-2 A/m 2 . This was caused by increase of compressive stress induced by Ar ion irradiation with low current density and stress relaxation by increased temperature during irradiation with high current density. The magnetic properties were found profoundly influenced by stresses induced by competitive factors such as irradiation damage and thermal annealing effect.

We measured current variation of carbonoized silicon-ˆeld emitter arrays (Si:C FEA) in hydrogen (H 2 ) ambient to show durability against hydrogen exposure. We operated both silicon-ˆeld emitter arrays (Si FEA) and Si:C FEA in H 2 atmosphere for 100 hours. Hydrogen gas is one of the major component of total residual pressure in ion implanter. As a result, the emission current from Si FEA decreased from 20 mA to 8 mA. But the emission current from Si:C FEA increased from 20 mA to 80 mA. It was shown that the durability of Si:C FEA against H 2 gas was better than that of Si FEA. . は じ め に