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- Garcia-Ben, Javier, et al.
(författare)
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Narrowing the tolerance factor limits for hybrid organic-inorganic dicyanamide-perovskites
- 2022
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Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 316, s. 123635-
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Tidskriftsartikel (refereegranskat)abstract
- In this work we focus in setting the limits of the tolerance factor and the size of the A-cations that stabilize the perovskite structure in hybrid dicyanamide compounds [A][Mn(dca)3]. For this purpose, we propose an alter-native, simple approach to calculate a more realistic effective ionic radius for the large and anisotropic A-cations often present in these type of compounds. We test the proposed procedure by analysing the crystal structures of [A][Mn(dca)3] dicyanamide hybrids reported in the literature and recalculating the tolerance factors of such compounds, as well as by preparing five new [A][Mn(dca)3] members, discussing also the influence of the A -cation shape in the stability limits of the perovskite structure. Interestingly, such methodology is not only useful to develop new compounds of the emerging family of (multi)functional multi(stimuli)-responsive dicyanamide materials but can also be applied to other hybrid organic-inorganic perovskites and related materials.
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| 2. |
- García-Ben, Javier, et al.
(författare)
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Structure and thermal property relationships in the thermomaterial di-n-butylammonium tetrafluoroborate for multipurpose cooling and cold-storage
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 11:41, s. 22232-22247
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Tidskriftsartikel (refereegranskat)abstract
- Nowadays around 46% of food production around the world requires refrigeration, which is generally provided either by active vapour-compression (based on refrigerants with liquid-gas transitions) or passive cold-storage (based on solid-to-liquid phase change materials, SL-PCMs). However, in order to avoid fluid losses during the transitions, new thermomaterials with solid-solid transitions are desired for both applications. In this work, we find that [DBA][BF4] (DBA = di-n-butylammonium) is a promising thermomaterial with solid-solid phase transitions. This compound presents thermal properties of great interest not only for active barocaloric refrigeration, but also for passive cold-storage, which make this a unique multipurpose thermomaterial. The observed cold-storage capacity is very close to that of commercial SL-PCMs (E ∼ 135 kJ kg−1), while the pressure-induced thermal changes (ΔS ∼ [200-270] J K−1 kg−1) are superior to those of most barocaloric materials, operating under lower pressures (p ∼ [500-1000] bar). Moreover, the operating temperature range of this material is very adequate for food preservation (250-310 K), which is a great advantage over most barocaloric materials. Beyond the thermal properties, we perform deep structural characterization, which reveals a progressive structural disorder of the [DBA]+ cations and [BF4]− anions as the origin of such thermal properties, which will help the future rational design of enhanced thermomaterials.
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