High-pressure single-crystal XRD and magnetic study of a octacyanoniobate-based magnetic sponge

Pinkowicz, Dawid; Kurpiewska, Katarzyna; Lewiński, K.; Bałanda, Maria; Mihalik, M.; Zentková, M.; Sieklucka, Barbara

doi:10.1039/c2ce25387a

Cited by 23 publications

(18 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The uniqueness of compound 9 is also related to the possibility of the change of the magnetic properties by the application of hydrostatic pressure [54]. The application of hydrostatic pressure of 1.8 GPa results in the compression of the unit cell (ca.…”

Section: [{[Mn II (Pydz)(h2o)2][mn Ii (H2o)2][nb Iv (Cn)8]}•2h2o]nmolmentioning

confidence: 99%

“…The summary of the magnetocaloric properties of all forms of molecular magnet 9 as well as results obtained for other octacyanoniobate-based compounds are presented in Table 4. The uniqueness of compound 9 is also related to the possibility of the change of the magnetic properties by the application of hydrostatic pressure [54]. The application of hydrostatic pressure of 1.8 GPa results in the compression of the unit cell (ca.…”

Section: [{[Mn II (Pydz)(h2o)2][mn Ii (H2o)2][nb Iv (Cn)8]}•2h2o]nmolmentioning

confidence: 99%

See 1 more Smart Citation

Multifunctional Molecular Magnets: Magnetocaloric Effect in Octacyanometallates

et al. 2018

Self Cite

View full text Add to dashboard Cite

Octacyanometallate-based compounds displaying a rich pallet of interesting physical and chemical properties, are key materials in the field of molecular magnetism. The [M(CN)8]n− complexes, (M = WV, MoV, NbIV), are universal building blocks as they lead to various spatial structures, depending on the surrounding ligands and the choice of the metal ion. One of the functionalities of the octacyanometallate-based coordination polymers or clusters is the magnetocaloric effect (MCE), consisting in a change of the material temperature upon the application of a magnetic field. In this review, we focus on different approaches to MCE investigation. We present examples of magnetic entropy change ΔSm and adiabatic temperature change ΔTad, determined using calorimetric measurements supplemented with the algebraic extrapolation of the data down to 0 K. At the field change of 5T, the compound built of high spin clusters Ni9[W(CN)8]6 showed a maximum value of −ΔSm equal to 18.38 J·K−1 mol−1 at 4.3 K, while the corresponding maximum ΔTad = 4.6 K was attained at 2.2 K. These values revealed that this molecular material may be treated as a possible candidate for cryogenic magnetic cooling. Values obtained for ferrimagnetic polymers at temperatures close to their magnetic ordering temperatures, Tc, were lower, i.e., −ΔSm = 6.83 J·K−1 mol−1 (ΔTad = 1.42 K) and −ΔSm = 4.9 J·K−1 mol−1 (ΔTad = 2 K) for {[MnII(pyrazole)4]2[NbIV(CN)8]·4H2O}n and{[FeII(pyrazole)4]2[NbIV(CN)8]·4H2O}n, respectively. MCE results have been obtained also for other -[Nb(CN)8]-based manganese polymers, showing significant Tc dependence on pressure or the remarkable magnetic sponge behaviour. Using the data obtained for compounds with different Tc, due to dissimilar ligands or other phase of the material, the ΔSm ~ Tc−2/3 relation stemming from the molecular field theory was confirmed. The characteristic index n in the ΔSm ~ ΔHn dependence, and the critical exponents, related to n, were determined, pointing to the 3D Heisenberg model as the most adequate for the description of these particular compounds. At last, results of the rotating magnetocaloric effect (RMCE), which is a new technique efficient in the case of layered magnetic systems, are presented. Data have been obtained and discussed for single crystals of two 2D molecular magnets: ferrimagnetic {MnII(R-mpm)2]2[NbIV(CN)8]}∙4H2O (mpm = α-methyl-2-pyridinemethanol) and a strongly anisotropic (tetren)Cu4[W(CN)8]4 bilayered magnet showing the topological Berezinskii-Kosterlitz-Thouless transition.

show abstract

Section: [{[Mn II (Pydz)(h2o)2][mn Ii (H2o)2][nb Iv (Cn)8]}•2h2o]nmolmentioning

confidence: 99%

Section: [{[Mn II (Pydz)(h2o)2][mn Ii (H2o)2][nb Iv (Cn)8]}•2h2o]nmolmentioning

confidence: 99%

Multifunctional Molecular Magnets: Magnetocaloric Effect in Octacyanometallates

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Mn 2 Nb (Figure 4) displays a very strong and linear increase of the T c from 23.4 K at ambient pressure to 36.5 K at 1.03 GPa. The linear fit of the T c (p) dependence (Figure 4c) leads to dT c /dp = 12.4 ± 0.2 K GPa −1 , typical for octacyanidoniobate(IV)-based systems and Prussian Blue analogs [2]. Fe 2 Nb, on the other hand, exhibits almost complete quenching of the long-range magnetic ordering under pressure, resulting in paramagnetic properties above 0.7 GPa ( Figure 5).…”

Section: Magnetic Properties Under High Pressurementioning

confidence: 96%

“…These types of studies make it possible to fine-tune the structure and physical properties in a continuous manner-a feature that cannot be achieved via chemical modifications, which often introduce unexpected complications (different packing modes, additional intra-and intermolecular contacts). The application of high pressure is known to be extremely useful for enhancing the magnetic ordering temperature of extended coordination systems [1][2][3][4][5], ligand field and magnetic anisotropy tuning of mononuclear complexes [6,7] and control of the spin crossover behavior [8,9]. The combined high-pressure single-crystal X-ray diffraction (scXRD) and SQUID magnetometry make a perfect set of tools to study and understand the changes induced by this type of mechanical stimulus.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

How to Quench Ferromagnetic Ordering in a CN-Bridged Ni(II)-Nb(IV) Molecular Magnet? A Combined High-Pressure Single-Crystal X-Ray Diffraction and Magnetic Study

et al. 2019

Self Cite

View full text Add to dashboard Cite

High-pressure (HP) structural and magnetic properties of a magnetic coordination polymer {[NiII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Ni2Nb) are presented, discussed and compared with its two previously reported analogs {[MnII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Mn2Nb) and {[FeII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Fe2Nb). Ni2Nb shows a significant decrease of the long-range ferromagnetic ordering under high pressure when compared to Mn2Nb, where the pressure enhances the Tc (magnetic ordering temperature), or to Fe2Nb exhibiting a pressure-induced spin crossover. The different HP magnetic responses of the three compounds were rationalized and correlated with the structural models as determined by single-crystal X-ray diffraction.

show abstract