Quantum signatures of a molecular nanomagnet in direct magnetocaloric measurements

Sharples, Joseph W. ; Collison, David ; McInnes, Eric J. L. ; Schnack, Juergen ; Palacios, Elias (Universidad de Zaragoza) ; Evangelisti, Marco (Universidad de Zaragoza)

Resumen: Geometric spin frustration in low-dimensional materials, such as the two-dimensional kagome or triangular antiferromagnetic nets, can significantly enhance the change of the magnetic entropy and adiabatic temperature following a change in the applied magnetic field, that is, the magnetocaloric effect. In principle, an equivalent outcome should also be observable in certain high-symmetry zero-dimensional, that is, molecular, structures with frustrated topologies. Here we report experimental realization of this in a heptametallic gadolinium molecule. Adiabatic demagnetization experiments reach B200 mK, the first sub-Kelvin cooling with any molecular nanomagnet, and reveal isentropes (the constant entropy paths followed in the temperature-field plane) with a rich structure. The latter is shown to be a direct manifestation of the trigonal antiferromagnetic net structure, allowing study of frustration-enhanced magnetocaloric effects in a finite system.

Idioma: Inglés

DOI: 10.1038/ncomms6321

Año: 2014

Publicado en: NATURE COMMUNICATIONS 5 (2014), 5321 [6 pp]
ISSN: 2041-1723

Factor impacto JCR: 11.47 (2014)

Categ. JCR: MULTIDISCIPLINARY SCIENCES rank: 3 / 57 = 0.053 (2014) - Q1 - T1

Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2012-38318-C03-01
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-44063-R

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Física de la Materia Condensada (Departamento de Física de la Materia Condensada)