Romanini, MichelaWang, YiXuGurpinar, Kübra.Ornelas, GladysLloveras, PolZhang, YanZheng, WenkaiBarrio, MaríaAznar, AraceliGràcia-Condal, AdriàEmre, BarisPopescu, CatalinZhang, HuLong, YiBalicas, LuisTamarit, Josep LluísPlanes Vila, AntoniShatruk, MichaelMañosa, Lluís2022-12-052022-12-052021-020935-9648https://hdl.handle.net/2445/191378A 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.9 p.application/pdfeng(c) Wiley-VCH, 2021Ciència dels materialsPropietats magnètiquesSuperconductivitatMaterials scienceMagnetic propertiesSuperconductivityinfo:eu-repo/semantics/article7089262022-12-05info:eu-repo/semantics/openAccess