人造層狀結構非晶態稀土--過渡元素多層薄膜磁性研究

Abstract

本論文實驗的主要目的,是探討人造層狀結構磁性薄膜垂直異向性的 能起 源.原子對之間各向異性分佈是我們討論這些磁特性的基礎,其途徑是以交 錯沉積(alternating deposition)的鍍膜方法,製作出人造層狀結構薄膜. 人造層狀結構的安排方式,將導致原子對之間各向異性分佈 (anisotropic distribution of atomic pairs),來自稀土,過渡金屬之間 的磁交互作用,其方向垂直於薄膜面.藉由人為的方式,改變多層膜中各膜 層的厚度,從而改變多層膜的物性.與具有相同平均成份的合金薄膜相比 較,人造層狀結構薄膜能表現出多樣的磁特性.在較為寬廣的TM膜厚範圍 內,多層薄膜具有磁光記錄媒體所需的垂直磁異向性.我們認為人造層狀結 構非晶態稀土--過渡元素多層薄膜具有成為磁光記錄媒體的潛力. Investigation of possible origin of perpendicular magnetic anisotropy of thin films with an artificially layered structure is studied. Anisotripy distribution of atomic pairs is the base throughout the discussion of this thesis. Thin films with antificially laminated structure were prepared by sputtering deposition in a sequential way. The arrangement of laminated structure leads to anisotropic distribution of constituent atomsar and far from the interfacial region, with excess of RE- TM atomic pairs perpendicular to the film plane and RE-RE AND TM-TM atomic pairs in the film plane. By properly adjusting the layer thickness, it is possible to tailor the magnetic properties in the multilayer structure. As compared with the same averagemposition of alloy thin films, nanoscale multilayer exhibited various magnetic properties. Multilayered thin films showrpendicular magnetic anisotropy over a wideer range of TMr thickness. We concluded that the amorphous RE-TM thin fimls with an artificially layered structure is potentiallyeful as magneto-optical storage media.