Cloaking the Static Magnetic Fields by Alternate Superconductor-Ferromagnet Heterostructure

• Published in: IEEE transactions on applied superconductivity Vol. 26; no. 4; pp. 1 - 5
• Main Authors: Zhou, Peng-Bo, Ma, Guang-Tong, Wang, Zhi-Tao, Gong, Tian-Yong, Ye, Chang-Qing, Zhang, Han
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Chromium steels; Constituents; Ferromagnetism; Frequency modulation; Helmholtz coil; Heterostructures; Magnetic cloaking; Magnetic field measurement; Magnetic fields; Magnetic flux; Magnetic multilayers; Magnetic permeability; magnetic shielding; Mathematical analysis; Mathematical models; Permeability; Stainless steels; Superconducting magnets; Superconductors; Coated superconductor; magnetic cloaking; superconductor (SC)-ferromagnet (FM) heterostructure; Helmholtz coil; magnetic shielding
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2016.2527686

The novel concept to well cloak the incident static magnetic fields by a heterostructure made of a superconductor (SC) and a ferromagnet (FM) has been proposed and verified recently. The performance of such heterostructure strongly depends on the involved materials and its geometrical configurations. We designed and built a practical version of a cylindrical multilayer cloak wound by an alternate SC-FM heterostructure that consists of a coated superconductor and a 1Cr17 ferromagnetic alloy. The cloaking properties of such hybrid against the static magnetic field generated by a Helmholtz coil were measured to verify the related finite-element model, in which the SC constituent is postulated as a diamagnet with relative permeability of less than 1. Using the verified model, we further carried out a set of finite-element simulations with experimentally derived permeability of both the SC and FM constituents to observe the dependence of the cloaking effect as well as the shielding efficiency of the SC-FM heterostructure on its geometry. The obtained characteristics of the magnetic cloaking of the SC-FM hybrid may offer a new paradigm for its applications in the military and medical devices.