Thermodynamic Measurements in Pulsed Magnetic Fields

Pulsed magnets provide the highest available magnetic fields for research. Non-destructive pulsed magnets that discharge a capacitor through an inductive load are routinely used to reach fields above 60 Teslas, and ever-higher fields are being targeted by a handful of laboratories around the world. The Dresden High Magnetic Field Laboratory (HLD) is one such cutting edge research facility [1]. Founded in 2003 [2], the HLD opened to users in 2007 and forms part of the Euromagnet network of high field laboratories. The Max Planck Society is integrated with the HLD at the ground level through the research program “Materials Science and Condensed Matter Research at the Hochfeld-Magnetlabor Dresden”, based at the MPI-CPfS [3]. Measurements in pulsed magnetic fields are subject to strong constraints that arise both from the short timescale of the experiments (some milliseconds) and the mechanical and electrical noise induced by the rapid discharge of the capacitors. It has therefore been difficult to explore thermodynamic properties of materials with high resolution; even measurements of basic transport properties are challenging. We have developed two thermodynamic probes for use in the pulsed magnetic fields which boast world-leading resolution. The specific heat experiment utilizes the adiabatic method with specific adaptations for pulsed-field work and the option for carrying out magnetocaloric effect measurements. The magnetostriction experiment sidesteps many of the limitations of the noisy environment by utilizing a novel optical method borrowed from the telecommunications industry. In the following we will present each method and some preliminary results on materials of interest.