A sacrificial magnet concept for field dependent surface science studies

Danyang Liu; Jens Oppliger; Aleš Cahlík; Catherine Witteveen; Fabian O von Rohr; Fabian Donat Natterer

doi:10.1016/j.mex.2022.101964

A sacrificial magnet concept for field dependent surface science studies

MethodsX. 2022 Dec 9:10:101964. doi: 10.1016/j.mex.2022.101964. eCollection 2023.

Authors

Danyang Liu¹, Jens Oppliger¹, Aleš Cahlík¹, Catherine Witteveen^{1

2}, Fabian O von Rohr², Fabian Donat Natterer¹

Affiliations

¹ Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
² Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland.

Abstract

We demonstrate a straightforward approach to integrating a magnetic field into a low-temperature scanning tunneling microscope (STM) by adhering an NdFeB permanent magnet to a magnetizable sample plate. To render our magnet concept compatible with high-temperature sample cleaning procedures, we make the irreversible demagnetization of the magnet a central part of our preparation cycle. After sacrificing the magnet by heating it above its Curie temperature, we use a transfer tool to attach a new magnet in-situ prior to transferring the sample into the STM. We characterize the magnetic field created by the magnet using the Abrikosov vortex lattice of superconducting NbSe_2. Excellent agreement between the distance dependent magnetic fields from experiments and simulations allows us to predict the magnitude and orientation of magnetic flux at any location with respect to the magnet and the sample plate. Our concept is an accessible solution for field-dependent surface science studies that require fields in the range of up to 400 mT and otherwise detrimental heating procedures.•Accessible magnetic field generation.•Selectable field strength and orientation.•Compatible with high-temperature sample preparation.

Keywords: Magnetic field; Magnetic field angle; STM, Scanning Tunneling Microscope; Sacrificial Magnet Concept; Superconducting vortex; Surface Science.