Ultracompact Binary Permanent Rare-Earth Magnet with 1.25-T Center Field and Fast-Decaying Stray Field

Abstract

We present a very-compact bicomponent-permanent-magnet design capable of generating 1.25 T in a small volume, significantly above the 0.6 T available from a single uniformly magnetized permanent magnet. In addition to the enhanced maximum field, our design drastically limits the stray field present around a standard permanent magnet. These features make it suitable for retrofitting existing experiments with a substantial magnetic field, in particular, scanning probes and optical, Raman, and photoemission spectroscopy, in diverse environments, from ambient to ultrahigh vacuum and over a wide temperature range.

A sacrificial magnet concept for field dependent surface science studies

“…NbSe 2 is a type-II superconductor with critical temperature of 7.2 K [4] that exhibits the well-known Abrikosov flux vortex-lattice when subjected to an external magnetic field in the superconducting state [5] . As each vortex is exactly penetrated by one flux quantum , the vortex-lattice parameter can be used to precisely measure the applied magnetic field [ 1 , 5 ]. We therefore determine the mean vortex separation d v from closed loop conductance scans at a bias voltage providing a good contrast between superconducting [ Fig.…”

“…2 (a) purple spectrum] and normal [ Fig. 2 (a) blue spectrum] state to evaluate the magnetic field for a triangular vortex lattice following [1] . Having a negligible in-plane component [see Fig.…”