State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an Shaanxi, 710072, China.
Univ. Grenoble Alps, LNCMI, F-38000, Grenoble, France.
Sci Rep. 2017 May 22;7(1):2248. doi: 10.1038/s41598-017-02610-6.
Magnetic field can generate interface instability when some liquids are put close to magnetic field. A well-known interface instability is called Rosensweig instability or normal field instability. Here we report that pure liquid Co can be highly undercooled close to its Curie temperature in strong magnetic field with very high magnetization and exhibiting unique morphology instability called the normal field instability. To obtain such unique instability pattern, the sample size, undercooling and magnetic field intensity need fulfill certain condition. In the present study, we have studied the required condition for obtaining normal field instability. The magnetization of the undercooled liquid Co is measured in a wide temperature range with different magnetic field intensities and calculated as a function of undercooling and field intensity. The critical size and critical magnetization for the normal field instability are calculated with the changing temperature and field intensity. Then the required conditions including the critical size, the minimum undercooling and field intensity for the existence of the instability pattern formation are determined.
磁场会使一些靠近磁场的液体产生界面不稳定性。一种众所周知的界面不稳定性称为罗森斯维格不稳定性或正常场不稳定性。在这里，我们报告说，在强磁场中，具有高磁化强度的纯液态 Co 可以在非常接近居里温度的情况下被高度过冷，并表现出一种独特的形态不稳定性，称为正常场不稳定性。为了获得这种独特的不稳定性模式，样品尺寸、过冷度和磁场强度需要满足一定的条件。在本研究中，我们研究了获得正常场不稳定性的所需条件。在不同磁场强度下，测量了过冷液态 Co 的磁化强度，并作为过冷度和场强的函数进行了计算。用变化的温度和场强计算了正常场不稳定性的临界尺寸和临界磁化强度。然后确定了存在不稳定性模式形成所需的条件，包括临界尺寸、最小过冷度和场强。
