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Magnetic effects by functional pressure and its application in magnetic keeper

功能压力产生的磁效应及其在磁力保持器中的应用

基本信息

批准号：
11671961
负责人：
HISATAKE Keizo
金额：
$ 1.09万
依托单位：
Kanagawa Dental College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11671961/
关键词：
magnetic after-effect disaccommodation functional pressure occulusion impact loading mechanical shock soft magnetic materials magnetic keeper イットリウム鉄ガーネット機械的刺戟アモルファス金属 (1)機能圧 (2)ディスアコモデーション (3)落下物体 (4)誘導磁気効果 (5)衝撃 (6)ソフト磁

项目摘要

In soft magnetic materials, the induced preferred directions within the domain wall often creates localized potential minima. As these minima become deeper with time, the mobility of the domain wall will decrease, associated with gradual decrease of initial permeability after demagnetization, so called, disaccommodation (DA). For the purpose of applying this phenomenon to the problem of mechanical shock in the process of occlusion or a functional pressure we observed an occurrence of DA and relation between DA and the strength of the shock in not only bulk single crystals of magnetic garnet such as yttrium iron garnets and spinel ferrites we observed for the first time, but also bulk polycrystalline sintered samples or single crystalline epitaxially grown thin films. The basic concept of our experiment is as follows. Although some loadings are static, any other ones are dynamic ; that is, they vary with time or an impact loading. A typical example could be caused by the collision of objects. When the block (m=100 g) is released from rest, it falls a distance h, then the impact loading is proportional to the quantity of the summation of mh and the square root of mh. We found the increase of the permeability in these single crystalline samples tends to be proportional to the quantity. In polycrystalline samples, the issue becomes yet further complicated due to the microstructure, which has been cleared from the many SEM photographs. The measurements of the impact loadings, with a strain-gauge-method were carried out. They are very complicated so that the oscillating parts of the signals are involved.

在软磁材料中，畴壁内的感应择优方向经常产生局部电势极小值。随着这些最小值随时间变得更深，畴壁的迁移率将降低，这与退磁后初始磁导率的逐渐降低有关，所谓的失稳（DA）。为了将这一现象应用于机械冲击问题的过程中的闭塞或功能的压力，我们观察到DA的发生和DA之间的关系和冲击的强度，不仅在大块单晶的磁性石榴石，如钇铁石榴石和尖晶石铁氧体，我们观察到的第一次，但也大块多晶烧结样品或单晶外延生长的薄膜。我们实验的基本概念如下。虽然有些载荷是静态的，但任何其他载荷都是动态的，即它们随时间或冲击载荷而变化。一个典型的例子可能是物体的碰撞。当块体（m=100 g）从静止状态释放时，它下落福尔斯距离h，则冲击载荷与mh和mh的平方根之和成正比。我们发现在这些单晶样品中磁导率的增加倾向于与量成正比。在多晶样品中，由于微观结构，问题变得更加复杂，这已经从许多SEM照片中清除。用应变片法测量了冲击载荷。它们非常复杂，因此涉及到信号的振荡部分。