Abstract
We report an in-depth study of the thermodynamic and magnetocaloric properties of a strongly frustrated magnet, Cs2Fe2(MoO4)3. The underlying structure belongs to the double trillium lattice, which consists of two FeII (S = 2) sites with easy-axis and easy-plane single-ion anisotropy. Detailed 57Fe Mössbauer spectroscopic investigations along with ligand-field calculations support the existence of disparate ground states. The antiferromagnetic ordered structure is presented by the propagation vector k = (0,0,0) with noncollinear magnetic moments of 2.97 μB (Fe1) and 0.17 μB (Fe2), respectively. Strong and disordered magnetic correlations exist in the temperature regime between TN ≈ 1.0 K and |θCW| ≈ 22 K. The large degeneracy of the ground state is investigated in terms of its magnetocaloric response. Magnetization and specific heat measurements indicate a significant magnetocaloric cooling efficiency, making this rare-earth-free compound a promising candidate for cryogenic magnetic refrigeration applications, with refrigeration capacity of 79 J kg-1 for Δ(μ0H) = 8 T.
| Original language | English |
|---|---|
| Pages (from-to) | 7016-7025 |
| Number of pages | 10 |
| Journal | Chemistry of Materials |
| Volume | 36 |
| Issue number | 14 |
| DOIs | |
| State | Published - Jul 23 2024 |
Funding
This work has received funding from the European Union\u2019s Research and Innovation Program Horizon Europe under the Marie Sk\u0142odowska-Curie Grant Agreement No. 101066568. Support from the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) under the projects 443703006 \u2013 CRC 1487 and 442589410 is gratefully acknowledged. 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. The beam time was allocated to the HB-2A beamline on Proposal Number IPTS-31426.1. We acknowledge M. Du\u0308rl and M. Schulz for help with the magnetic measurements and sample preparation.