ausblenden:
Schlagwörter:
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Zusammenfassung:
The metal-organic framework
{[Fe(2,2'-bipyridine)(CN)(4)](2)Co-(4,4'-bipyridine)}center dot 4H(2)O
(Fe2Co-MOF) with single-chain magnetism undergoes an intermetallic
charge transfer that converts the Fe2Co charge/spin configurations from
Fe-LS(3+)-Co-HS(2+)-Fe-LS(3+) to Fe-LS(2+)-Co-LS(3+)-Fe-LS(3+) (LS = low
spin, HS = high spin) around 220 K under ambient pressure. A series of
coherent phase transitions in structure, magnetism, permittivity and
ferroelectricity are found to take place accompanying with the charge
transfer, making Fe2Co-MOF a unique ferroelectric single-chain magnet at
low temperature. Moreover, our detailed measurements of magnetization,
dielectric constant, and Raman scattering under high pressures
illustrate that the charge transfer as well as the resulting
multifunctional transitions can be readily induced to occur at room
temperature by applying a tiny external pressure of about 0.5 kbar. The
present study thus provides a pressure well-controllable multifunctional
material with potential applications in a broad temperature region
across room temperature.
