In this article a simple and easy to install low magnetic field extension of the SQUID magnetometer Quantum Design MPMS-7 is described. This has been accomplished by complementing the MPMS-7 magnet control system with a laboratory current supply for the low magnetic field region (B \leq 200G). This hard- and software upgrade provides a significant gain in the magnetic field accuracy up to an order of magnitude compared with the standard instrument's setup and is improving the resolution to better than 0.01G below 40G. The field control has been integrated into the Quantum Design MultiVu software for a transparent and user-friendly operation of this extension. The improvements achieved are especially useful, when low magnetic field strengths (B < 1G) are required at high precision. The specific advantages of this application are illustrated by sophisticated magnetic characterisation of lowdimensional superconductors like Sc3CoC4 and SnSe2{Co({\eta}-C5H5)2}x.
@article{arxiv.0806.1663,
title = {Low field extension for magnetometers (TinyBee) used for investigations on low-dimensional superconductors with Bc1 < 5G},
author = {M. Presnitz and M. Herzinger and E. -W. Scheidt and W. Scherer and M. Baenitz and M. Marz},
journal= {arXiv preprint arXiv:0806.1663},
year = {2013}
}