Magnetocaloric and barocaloric effects of metal complexes for solid state cooling: Review, trends and perspectives

Reis, M. S.

doi:10.1016/j.ccr.2020.213357

Cited by 59 publications

(32 citation statements)

References 84 publications

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“…Magnetic isotropy and high ground spin-state are two factors that favour the observation of a large magneto-caloric effect (MCE) [15,[40][41][42][43][44]. Moreover, if the magnetic exchange interaction between the metal ions is weak, a large MCE could be attained [15,[40][41][42][43][44]. Thus, the isotropic nature of the Cu II and Gd III ions and the weak ferromagnetic exchange interactions, as well as the relatively large metal/ligand mass ratio (which limits the amount of passive, non-magnetic elements) makes compound 1 a good candidate to display large MCE.…”

Section: Magneto-thermal Propertiesmentioning

confidence: 99%

“…In the systems in which the magnetic interactions are not strong enough and/or the magnetic anisotropy is not large enough for the appearance of slow relaxation of the magnetization, other exciting physical phenomena such as the magneto-caloric effect (MCE) can still be studied [15]. The multiple low-lying excited and field-accessible states generated in such compounds contribute to the overall magnetic entropy, which can be modulated upon the application of an external magnetic field.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

et al. 2021

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New dinuclear MII-LnIII complexes of general formulas [Cu(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN·H2O (LnIII = Gd (1), Tb (2), Dy (3) and Er (4)), [Ni(CH3CN)(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (LnIII = Nd (5), Gd (6), Tb (7), Dy (8), Er (9) and Y (10)) and [Co(CH3CN)(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (LnIII = Gd (11), Tb (12), Dy (13), Er (14) and Y (15)) were prepared from the compartmental ligand N,N′-dimethyl-N,N′-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these complexes, the transition metal ions occupy the internal N2O2 coordination site of the ligand, whereas the LnIII ions lie in the O4 external site. Both metallic ions are connected by an acetate bridge, giving rise to triple mixed diphenoxido/acetate bridged MIILnIII compounds. Direct current (dc) magnetic measurements allow the study of the magnetic exchange interactions between the 3d and 4f metal ions, which is supported by density functional theory (DFT) theoretical calculations for the GdIII-based counterparts. Due to the weak ferromagnetic exchange coupling constants obtained both experimentally and theoretically, the magneto-thermal properties of the less anisotropic systems (compounds 1 and 6) are also studied. Alternating current (ac)magnetic measurements reveal the occurrence of slight frequency dependency of the out-of-phase signal for complexes 8, 9 and 13, while complex 15 displays well-defined maximums below ~6 K.

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Section: Magneto-thermal Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

et al. 2021

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“…[ 46 ] Our calculations are in good agreement with the experimental data, obtained indirectly for SCO materials. [ 27 ] The maximum ΔS T and ΔT ad values occur around the HS–LS phase transition, which can be tuned with pressure. Our investigated material display high and constant value of

δ T_{1 / 2} / δ P

in the pressure interval from 0 to 5 kbar, i.e., a linear dependence of T 1/2 on pressure.…”

Section: Discussionmentioning

confidence: 99%

“…From the theoretical microscopic model, these three contributions basically depend on 1) the HS molar concentration values, γ HS , 2) spin values s LS and s HS of the metal ions inside the ligands, and 3) their vibrational frequencies. [26,27] The aim of this study is to determine the barocaloric effect and refrigerant capacity in the SCO complex {Fe[H 2 B(pz) 2 ] 2 (bipy)} (bipy ¼ 2,2 0 -bipyridine). [28] The experimental data of ΔS T and ΔT ad were indirectly obtained through the interpolation of temperature and pressure dependence of the HS molar concentration, γ HS (T, P), measured by magnetic susceptibility.…”

Section: Introductionmentioning

confidence: 99%

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Refrigeration through Barocaloric Effect Using the Spin Crossover Complex {Fe[H₂B(pz)₂]₂(bipy)}

Ranke

Alho

Silva

et al. 2021

Physica Status Solidi (b)

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Spin crossover complexes have a very striking signature of a huge volume change coupled with low–high spin conversion around a critical temperature, which can be pressure tuned in a large temperature interval. Herein, the barocaloric effect is reported in the spin crossover complex {Fe[H2B(pz)2]2(bipy)} (bipy = 2,2′‐bipyridine) from theoretical and applied points of view. The experimental data reveal a giant barocaloric effect, through the isothermal entropy change (ΔST = 83 J kg−1 K−1) around T = 273 K, upon moderated hydrostatic pressure variation (ΔP = 2 kbar). The high and linear behavior in the pressure dependence of the phase transition temperature (19 K kbar−1) leads to a huge relative cooling power (RCP = 7296 J kg−1) upon ΔP = 3 kbar, which is discussed using Ericsson's cooling cycle. Theoretical results, obtained from a microscopic model, updated with the vibration modes from density functional theory (DFT) calculation, show remarkable agreement with the experimental data.

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Reversible Colossal Barocaloric Effect of a New Fe^II Molecular Complex with Low Hysteretic Spin Crossover Behavior

Seredyuk,

Li,

Znovjyak

et al. 2024

Adv Funct Materials

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Barocaloric cooling, that is, lowering the temperature of a material under pressure action, is an attractive solid‐state effect that can potentially compete with volatile gas‐based cooling. To observe the barocaloric effect (BCE), it is necessary for materials to have high‐entropy, low‐hysteretic phase transitions with a large volume change between phases. Here details on a new FeII complex [Fe(L)(NCS)2], L = N1,N3‐bis((1‐propyl‐1H‐1,2,3‐triazol‐4‐yl)methylene)‐2,2‐dimethylpropane‐1,3‐diamine) possessing spin crossover (SCO) behavior near room temperature with large entropy and volume change are reported, which provides high sensitivity to external pressure. The observed BCE effect, characterized using variable pressure calorimetry, powder X‐ray diffraction, UV–vis, IR, and Raman spectroscopy, shows a colossal isothermal entropy change of >100 J kg−1 K−1 and a reversible adiabatic temperature change of ≈16 K at a pressure of 1 kbar, demonstrating a high refrigerant efficiency compared to other solid‐state materials. These results stimulate further investigations of SCO materials as barocaloric refrigerants, which depend on the proper design of their constituent organic ligands.

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Magnetocaloric and barocaloric effects of metal complexes for solid state cooling: Review, trends and perspectives

Cited by 59 publications

References 84 publications

Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

Refrigeration through Barocaloric Effect Using the Spin Crossover Complex {Fe[H₂B(pz)₂]₂(bipy)}

Reversible Colossal Barocaloric Effect of a New Fe^II Molecular Complex with Low Hysteretic Spin Crossover Behavior

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Magnetocaloric and barocaloric effects of metal complexes for solid state cooling: Review, trends and perspectives

Cited by 59 publications

References 84 publications

Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes

Refrigeration through Barocaloric Effect Using the Spin Crossover Complex {Fe[H2B(pz)2]2(bipy)}

Reversible Colossal Barocaloric Effect of a New FeII Molecular Complex with Low Hysteretic Spin Crossover Behavior

Contact Info

Product

Resources

About

Refrigeration through Barocaloric Effect Using the Spin Crossover Complex {Fe[H₂B(pz)₂]₂(bipy)}

Reversible Colossal Barocaloric Effect of a New Fe^II Molecular Complex with Low Hysteretic Spin Crossover Behavior