2007/03/31 by T. W. Kornack, S. J. Smullin, S. -K. Lee +2 · 1 citation
Engineering · Physics and Astronomy · #Atomic and Subatomic Physics Research #Characterization and Applications of Magnetic Nanoparticles #Magnetic properties of thin films #physics.atom-ph #physics.ins-det
paper · pdf · doi:10.1063/1.2737357
published as Appl. Phys. Lett. 90, 223501 (2007) · 4 pages, 3 figures. Published in Appl. Phys. Lett.; replacement reflects published work
openalex publication_date 2007/05/28 · arxiv created 2007/07/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Ferrite materials provide magnetic shielding performance similar to commonly used high permeability metals but have lower intrinsic magnetic noise generated by thermal Johnson currents due to their high electrical resistivity. Measurements inside a ferrite shield with a spin-exchange relaxation-free atomic magnetometer reveal a noise level of 0.75fTHz−1∕2, 25 times lower than what would be expected in a comparable μ-metal shield. The authors identify a 1∕f component of the magnetic noise due to magnetization fluctuations and derive general relationships for the Johnson current noise and magnetization noise in cylindrical ferromagnetic shields in terms of their conductivity and complex magnetic permeability.