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Giant and reversible barocaloric effect in trinuclear spin-crossover complex Fe3(bntrz)6(tcnset)6
- Source :
- UPCommons. Portal del coneixement obert de la UPC, Universitat Politècnica de Catalunya (UPC)
- Publication Year :
- 2021
-
Abstract
- A giant barocaloric effect (BCE) in a molecular material Fe3 (bntrz)6 (tcnset)6 (FBT) is reported, where bntrz = 4-(benzyl)-1,2,4-triazole and tcnset = 1,1,3,3-tetracyano-2-thioethylepropenide. The crystal structure of FBT contains a trinuclear transition metal complex that undergoes an abrupt spin-state switching between the state in which all three FeII centers are in the high-spin (S = 2) electronic configuration and the state in which all of them are in the low-spin (S = 0) configuration. Despite the strongly cooperative nature of the spin transition, it proceeds with a negligible hysteresis and a large volumetric change, suggesting that FBT should be a good candidate for producing a large BCE. Powder X-ray diffraction and calorimetry reveal that the material is highly susceptible to applied pressure, as the transition temperature spans the range from 318 at ambient pressure to 383 K at 2.6 kbar. Despite the large shift in the spin-transition temperature, its nonhysteretic character is maintained under applied pressure. Such behavior leads to a remarkably large and reversible BCE, characterized by an isothermal entropy change of 120 J kg-1 K-1 and an adiabatic temperature change of 35 K, which are among the highest reversible values reported for any caloric material thus far.
- Subjects :
- Superconductivity
Materials science
Spin transition
Thermodynamics
Física::Física de l'estat sòlid [Àrees temàtiques de la UPC]
02 engineering and technology
Calorimetry
Crystal structure
010402 general chemistry
01 natural sciences
Isothermal process
Transition metal
Spin crossover
Magnetic properties
General Materials Science
Superconductivitat
Propietats magnètiques
Refrigerants
Mechanical Engineering
Transition temperature
Ciència dels materials
021001 nanoscience & nanotechnology
0104 chemical sciences
Hysteresis
Solid state physics
Mechanics of Materials
Física de l'estat sòlid
0210 nano-technology
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- UPCommons. Portal del coneixement obert de la UPC, Universitat Politècnica de Catalunya (UPC)
- Accession number :
- edsair.doi.dedup.....e9893356b33d508638487e5f3c46825e
- Full Text :
- https://doi.org/10.1002/adma.202008076