  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 NbSe2. 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.
