用现场洛伦茨显微镜研究磁域墙壁动态,使用定制的霍尔效应传感器支架
Mari Honkanen1, Henri Lukinmaa2, Sami Kaappa3
1Tampere Microscopy Center, Tampere University, P.O. Box 692, 33014 Tampere University, Finland.
Ultramicroscopy
|May 4, 2024
概括
我们开发了一种霍尔效应传感器支架,用于在传输电子显微镜 (TEM) 内测量磁流密度. 这种工具使得研究磁域壁的动态成为可能,揭示了状碳化物作为强大的固定点.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 磁力学 磁力学 是一种
背景情况:
- 了解磁域壁 (DW) 行为对于磁性材料至关重要.
- 在传输电子显微镜 (TEM) 中的现场表征提供了独特的见解.
- 测量TEM组件产生的磁场对于受控实验至关重要.
研究的目的:
- 开发和验证一个定制的霍尔效应传感器支架,用于在TEM内部进行现场磁场测量.
- 在外部施加的磁场下,研究铁素-珍珠钢中磁域壁的动力学.
- 为了将DW行为的实验观测与微磁模拟相关联.
主要方法:
- 制造定制的霍尔效应传感器支架,用于在TEM内精确测量磁流密度.
- 在现场的洛伦茨显微镜观察磁域壁 (DW) 动态.
- 使用TEM的客观镜头应用外部磁场.
- 动态微磁模拟以建模DW行为.
主要成果:
- 客观镜头表现出几乎线性响应,在关闭时几乎为零场.
- 铁质矩阵中垂直于状碳化物的磁域壁在10mT左右开始运动.
- 球状碳化物中的DW消失在160mT左右,和接近210mT.
- 状碳化物充当强大的固定点,保持高达288mT的DWs.
- 微磁模拟成功地重现了在球状碳化物中DW消失的实验观测.
结论:
- 定制的霍尔效应传感器持有器有效用于在TEM中的in-situ磁场量化.
- 铁-珠钢中的板状碳化物显著阻碍磁域壁的运动.
- 微磁模拟提供了一个可靠的工具来解释实验性DW动态.
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