학술논문
Giant pressure dependence and dimensionality switching in a metal-organic quantum antiferromagnet
Document Type
Working Paper
Author
Wehinger, Björn; Fiolka, Christoph; Lanza, Arianna; Scatena, Rebecca; Kubus, Mariusz; Grockowiak, Audrey; Coniglio, William A.; Graf, David; Skoulatos, Markos; Chen, Jyong-Hao; Gukelberger, Jan; Casati, Nicola; Zaharko, Oksana; Macchi, Piero; Krämer, Karl W.; Tozer, Stan; Mudry, Christopher; Normand, Bruce; Rüegg, Christian
Source
Phys. Rev. Lett. 121, 117201 (2018)
Subject
Language
Abstract
We report an extraordinary pressure dependence of the magnetic interactions in the metal-organic system [(CuF$_2$(H$_2$O)$_2$)$_2$pyrazine]. At zero pressure, this material realizes a quasi-two-dimensional (Q2D) spin-1/2 square-lattice Heisenberg antiferromagnet. By high-pressure, high-field susceptibility measurements we show that the dominant exchange parameter is reduced continuously by a factor of 2 upon compression. Above 18 kbar, a phase transition occurs, inducing an orbital re-ordering that switches the dimensionality, transforming the Q2D lattice into weakly coupled chains (Q1D). We explain the microscopic mechanisms for both phenomena by combining detailed x-ray and neutron diffraction results with quantitative modeling using spin-polarized density functional theory.
Comment: Revised manuscript. Crystallographic information files are contained in the source, please select Download "Other formats"
Comment: Revised manuscript. Crystallographic information files are contained in the source, please select Download "Other formats"