Unveiling the Structural, Electronic and Magnetic Properties of Gd4.5A0.5Si3O13 (A = K, Na, and Li) Oxides With
Yikun Zhang1, Jia Yan Law2, Angsai Li1
1Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University, Hangzhou, 310018, China.
Abstract:
The growing demand for solid-state magnetic cooling, leveraging the magnetocaloric effect requires the discovery of high-performing magnetocaloric materials (MCMs). Herein, a family of Gd-containing MCMs is provided, specifically the Gd4.5A0.5Si3O13 (A = K, Na, and Li) oxides, which demonstratse exceptional low-temperature magnetocaloric performance. Through comprehensive experimental investigations and theoretical calculations on their structural, electronic, and magnetic properties, it is unequivocally confirmed that all of them crystallize in a hexagonal apatite-type structure (space group P63/m), exhibiting an antiferromagnetic semiconductor ground state with magnetic ordering temperatures below 1.8 K (typically ≈0.7 K for Gd4.5K0.5Si3O13). Furthermore, their remarkable maximum magnetic entropy change (-ΔSM max) values of 31.85 and 58.22 J kgK-1 for Gd4.5K0.5Si3O13; 25.31 and 55.01 J kgK-1 for Gd4.5Na0.5Si3O13; and 25.15 and 55.77 J kgK-1 for Gd4.5Li0.5Si3O13, under the magnetic field changes of 0-2 and 0-5 T, respectively, surpass those of prominent low-temperature MCMs, including the commercialized Gd3Ga5O12 (≈14.6 and 32.8 J kgK-1) paramagnetic salt. These findings in addition to their high environmental stability position these Gd4.5A0.5Si3O13 oxides as exceptionally promising for practical magnetic cooling applications.
Related Concept Videos
01:28Types Of Superconductors
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:31Ferromagnetism
02:54Trends in Lattice Energy: Ion Size and Charge
02:54Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...