title: Magnetic nanopantograph in the SrCu2(BO3)2 Shastry-Sutherland lattice.
abstract: Magnetic materials having competing, i.e., frustrated, interactions can display magnetism prolific in intricate structures, discrete jumps, plateaus, and exotic spin states with increasing applied magnetic fields. When the associated elastic energy cost is not too expensive, this high potential can be enhanced by the existence of an omnipresent magnetoelastic coupling. Here we report experimental and theoretical evidence of a nonnegligible magnetoelastic coupling in one of these fascinating materials, SrCu2(BO3)2 (SCBO). First, using pulsed-field transversal and longitudinal magnetostriction measurements we show that its physical dimensions, indeed, mimic closely its unusually rich field-induced magnetism. Second, using density functional-based calculations we find that the driving force behind the magnetoelastic coupling is the CuOCu superexchange angle that, due to the orthogonal Cu(2+) dimers acting as pantographs, can shrink significantly (0.44%) with minute (0.01%) variations in the lattice parameters. With this original approach we also find a reduction of ∼ 10% in the intradimer exchange integral J, enough to make predictions for the highly magnetized states and the effects of applied pressure on SCBO.
authors: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie Sorbonne Universités-Université Pierre et Marie Curie Université Paris 06, UMR CNRS 7590, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement UMR 206, F-75005 Paris, France;
authors: Guillaume
authors: G
authors: Radtke
authors: Aix-Marseille University, Centre Interdisciplinaire de Nanoscience de Marseille-CNRS UMR 7325 Campus de Luminy, 13288 Marseille cedex 9, France; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology and MultiScale Material Science for Energy and Environment, UMI 3466 CNRS-MIT, Cambridge, MA 02139; saul@cinam.univ-mrs.fr.
authors: Andrés
authors: A
authors: Saúl
authors: McMaster University, Brockhouse Institute for Materials Research, Hamilton, ON L8S 4M1, Canada;
authors: Hanna A
authors: HA
authors: Dabkowska
authors: Department of Physics, The University of Texas at Dallas, Richardson, TX 75080; and National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545.
authors: Myron B
authors: MB
authors: Salamon
authors: National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545.
authors: Marcelo
authors: M
authors: Jaime
keywords: Shastry–Sutherland; density functional theory; high magnetic fields; magnetostriction; spin-lattice coupling
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