日本日立制作所所属中央研究所发现了利用电子束全息照相术,以5毫微米的分辨率观测磁场的方法。用于观测的试样是厚度为50毫微米的钴薄膜。在此试样上,用间隙为0.2微米的磁头以0.15微米的间隔进行磁记录。钴薄膜是在玻璃基板上以对基板表面呈倾斜的方向进行蒸镀而作成。这样,钴粒子在基板表面呈倾斜排列。在这一倾倒方向进行写入,便能使作为磁记录单位的磁区知磁区之间的磁壁,缩小至以往的十分之一左右。这样进行记录后,即可从玻璃基板上把钴薄蟆剥下。钴薄膜与玻璃基板之间是预先用光致抗蚀剂加以间隔的,因此只要将这层光致抗蚀剂熔化即可剥下钴薄膜。在经上述方法处理、并作过磁记录的钴薄膜试 The Central Institute of Hitachi, Ltd., Japan, discovered a method of observing a magnetic field using electron beam holography at a resolution of 5 nanometers. The sample used for observation is a cobalt film having a thickness of 50 nm. On this sample, magnetic recording was performed at a pitch of 0.15 micrometer with a magnetic head having a gap of 0.2 micrometer. A cobalt thin film is formed by vapor-depositing on a glass substrate in the direction which inclined the board | substrate surface. In this way, the cobalt particles are arranged in a slanting manner on the surface of the substrate. Writing in this direction of dumping can reduce the magnetic wall between the magnetization regions of the magnetic regions serving as magnetic recording units to about one tenth of the conventional ones. After recording in this way, the cobalt frog can be peeled off from the glass substrate. The cobalt film and the glass substrate are previously separated by a photoresist, so that the cobalt film can be peeled off just by melting the photoresist. In the above method of treatment, and made magnetic recording of cobalt film test