Quantum signatures of a molecular nanomagnet in direct magnetocaloric measurements

• DOI: 10.1038/ncomms6321
• Publication Date: 2014-10-22T11:13:47Z
• Authors: Joseph W. Sharples; David Collison; Eric J. L. McInnes; Jürgen Schnack; Elias Palacios; Marco Evangelisti
• Keywords: Nanomagnet; Magnetic refrigeration

Abstract Geometric spin frustration in low-dimensional materials, such as the two-dimensional kagome or triangular antiferromagnetic nets, can significantly enhance change of magnetic entropy and adiabatic temperature following a applied field, that is, magnetocaloric effect. In principle, an equivalent outcome should also be observable certain high-symmetry zero-dimensional, molecular, structures with frustrated topologies. Here we report experimental realization this heptametallic gadolinium molecule. Adiabatic demagnetization experiments reach ~200 mK, first sub-Kelvin cooling any molecular nanomagnet, reveal isentropes (the constant paths followed temperature-field plane) rich structure. The latter is shown to direct manifestation trigonal net structure, allowing study frustration-enhanced effects finite system.