ニッケルー鉄合金めっき膜中の水素および空孔の安定化熱処理

摘要

本論文は，優れた軟磁気特性をもつことで知られるニッケ ルー鉄合金めっき膜の物性を安定化させるために，めっき膜 中に過飽和に取り込まれた水素および空孔の経時変化を抑制 する熱処理条件を策定し，その効果を確認することを目的と している． ニッケルー鉄合金は，組成の違いにより高透磁率・低線膨 張係数などの優れた特性を示すため，電気・電子材料として 実用化されている．%In an effort to realize the long-term stability of the magnetism of electrodeposited Ni-Fe alloy films, heat treatments needed for eliminating the possible effect of hydrogen and metal-atom vacancies have been investigated, mainly by use of thermal desorption spectroscopy. While metal-atom vacancies begin to move only above 480 K, hydrogen atoms can undergo slow motion and concomitant changes of states at room temperature, and are therefore believed to be a major cause of the long-term drift of the magnetism. Hydrogen atoms dissolved on regular interstitial sites can be completely removed by high-frequency pulse heating to 668 K, and those trapped by vacancies with relatively low binding energies can be removed by additional heat treatments at 453 K for over 1 h. The effectiveness of using this set of heat treatments to stabilize the performance of magnetostrictive Ni-Fe film sensors has been verified.