Abstract
Van der Waals (vdW) magnets both allow exploration of fundamental 2D physics and offer a route toward exploiting magnetism in next generation information technology, but vdW magnets with complex, noncollinear spin textures are currently rare. We report here the syntheses, crystal structures, magnetic properties and magnetic ground states of four bulk vdW metal-organic magnets (MOMs): FeCl2(pym), FeCl2(btd), NiCl2(pym), and NiCl2(btd), pym = pyrimidine and btd = 2,1,3-benzothiadiazole. Using a combination of neutron diffraction and bulk magnetometry we show that these materials are noncollinear magnets. Although only NiCl2(btd) has a ferromagnetic ground state, we demonstrate that low-field hysteretic metamagnetic transitions produce states with net magnetization in zero-field and high coercivities for FeCl2(pym) and NiCl2(pym). By combining our bulk magnetic data with diffuse scattering analysis and broken-symmetry density-functional calculations, we probe the magnetic superexchange interactions, which when combined with symmetry analysis allow us to suggest design principles for future noncollinear vdW MOMs. These materials, if delaminated, would prove an interesting new family of 2D magnets.
| Original language | English |
|---|---|
| Pages (from-to) | 19146-19159 |
| Number of pages | 14 |
| Journal | Journal of the American Chemical Society |
| Volume | 146 |
| Issue number | 28 |
| DOIs | |
| State | Published - Jul 17 2024 |
Funding
M.J.C. and J.P. acknowledge funding from EPSRC Grant No. EP/X042782/1. High field magnetometry measurements were carried out using the Advanced Materials Characterisation Suite, funded by EPSRC Strategic Equipment Grant EP/M000524/1EPSRC. Computing resources were provided by the University of Birmingham’s BlueBEAR HPC service and the Sulis Tier 2 HPC platform (EP/T022108/1), with networking support by CCP-NC (EP/T026642/1), CCP9 (EP/T026375/1), and UKCP (EP/X035891/1). A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Andrew Jones is thanked for assistance with UV-visible spectroscopy measurements. M.J.C. and J.P. acknowledge funding from EPSRC Grant No. EP/X042782/1. High field magnetometry measurements were carried out using the Advanced Materials Characterisation Suite, funded by EPSRC Strategic Equipment Grant EP/M000524/1EPSRC. Computing resources were provided by the University of Birmingham’s BlueBEAR HPC service and the Sulis Tier 2 HPC platform (EP/T022108/1), with networking support by CCP-NC (EP/T026642/1), CCP9 (EP/T026375/1), and UKCP (EP/X035891/1). A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Andrew Jones is thanked for assistance with UV–visible spectroscopy measurements.