Metal organic framework Cu9Cl2(cpa)6 as tunable molecular magnet
| Autor: | Samuel F. Skinner, William M. Farmer, Heather S. C. Hamilton, Leonard W. ter Haar |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Phase transition
Materials science Condensed matter physics Magnetism Heisenberg model General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences lcsh:QC1-999 Magnetization Ferromagnetism Ferrimagnetism 0103 physical sciences Magnetic refrigeration 010306 general physics 0210 nano-technology Ground state lcsh:Physics |
| Zdroj: | AIP Advances, Vol 8, Iss 5, Pp 055802-055802-6 (2018) |
| ISSN: | 2158-3226 |
| Popis: | Chemical modifications of the magnetic metal organic framework (MOF) Cu9X2(cpa)6·42H2O (X = F, Cl, Br; cpa = anion of 2-carboxypentonicacid) have been investigated as a means of modifying, in a tunable manner, the magnetism of this 2-D material best described as a triangles-in-triangles (TIT) or triangulated-Kagome-latttice (TKL). Since numerous theoretical studies have already attempted to describe the enigmatic ground state of this Heisenberg lattice, tunable chemical modifications should provide an excellent opportunity to expand this class of materials for studies concerning fundamental physics of frustrated spins, and applications such as adiabatic demagnetization refrigeration (ADR) that depend on the magnetocaloric effect (MCE). The chemical modification investigated is the intercalation of d- and f-orbital ions into the voids of the framework (channels of nearly 20 A diameter). Magnetic measurements in the temperature range 1.8 – 300 K confirm signature features of TKL magnetism in intercalated samples persist, specifically: i) large negative Weiss constant (θCW); ii) absence of a phase transition down to 1.8 K; iii) minimum in χMT; iv) low temperature χMT values increasingly divergent at low fields indicating net ferromagnetic correlations; and, v) increasing field dependence of magnetization at low temperatures suggestive of intermediate plateaus, or ferrimagnetism, not saturation. |
| Databáze: | OpenAIRE |
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