Method and Development of an In-Situ, Optical Measurement of Shock Demagnetization in Single-Crystal Ferrimagnets
Technical Report,01 Jul 2018,01 Jul 2019
CCDC Army Research Laboratory Aberdeen Proving Ground United States
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Magnetic behavior coupled to the rapid dynamics of shock is relatively unexplored and warrants further investigation. This work reports on the development of an all-optical magnetization detection system, capable of resolving changes in the magnetic landscape on impact-relevant timescales. Classical demagnetization measurements are inherently bulk, providing little to no direct microscopic information. Optical techniques provide a wealth of rich information and have yet to be applied to the complicated dynamic magnetic landscape during shock. Magnetized materials exhibit circular birefringence, which modifies the polarization state of reflected and transmitted light. As a result, linearly polarized light propagating through the magnetized material is rotated, known as Faraday rotation. This change is a direct measurement of the degree and direction of the magnetization through which the light propagated. As we seek novel applications exploiting electromagnetism, understanding the magneto-mechanics physics will become increasingly important. To that end, we designed and built a setup to measure Faraday rotation of a 780-nm probe laser passed through single-crystal yttrium iron garnet during impact of laser-induced shock waves.
- Electricity and Magnetism
- Optical Detection and Detectors