A multiferroic material [NH2-CH+-NH2]Co(HCOO)3 of metal-organic frameworks with weak ferromagnetism and dielectric relaxation

Abstract

In order to seek for the single-phase multiferroic metal-organic frameworks (MOFs) materials, we prepared a multiferroic material [NH2-CH+-NH2]Co(HCOO)3 (FMDCo) by solvothermal method. We found that it had weak ferromagnetism below 12.5 K with the coercive fields (Hc) of 560 Oe, remnant magnetization (Mr) of 7.67 emu/g and saturation magnetization (Ms) of 10.3 emu/g and exhibited obvious dielectric relaxation. The octahedral metal ions (Co2+) were linked by formate (HCOO-) ligands. The AmineH+ cation (NH2-CH+-NH2) were located within the cube-like cavities of the framework and formed extensive hydrogen bonds with the framework. This improved the phase transition temperature and thermal stability. This finding helps to understand the nature of magnetic and electric ordering in the MOFs.

Recent Progress of Multiferroicity and Magnetoelectric Effects in ABX3‐Type Perovskite Metal–Organic Frameworks

“…For example, [Fmd][ M (HCOO) 3 ] ( M = Mn, Fe, Co, Cu), all compounds are ferromagnetic‐like materials. [ 26–28 ] From our point of view, the MOFs containing Fmd + should present the ferroelectric properties in addition to ferromagnetic behaviors, which has not been confirmed experimentally. Ferroelectric characteristics have been reported in other MOFs with similar structures.…”

“…Reproduced under terms of the CC‐BY license. [ 28 ] Copyright 2017, the Authors, published by AIP Publishing.…”

“…Copyrith 2014, The Authors, published by American Chemical Society. Temperature dependence of dielectric constant d), loss e) measured at different frequencies for Fmd-Co. Reproduced under terms of the CC-BY license [28]. Copyright 2017, the Authors, published by AIP Publishing.…”

A new avenue to relaxor-like ferroelectric behaviour found by probing the structure and dynamics of [NH3NH2]Mg(HCO2)3

“…Other AB(HCO 2 ) 3 phases and related hybrid perovskites with A-site cations that form significant hydrogen bonds exhibit dielectric anomalies similar to relaxor ferroelectrics. 22,24,25,[27][28][29]55 These relaxor-like properties are currently not clearly explained and it is likely that related mechanisms may apply to a significant number of them.…”

“…20,21 Recently there have been reports of inorganic-organic hybrid perovskites and closely related phases with dielectric properties similar to relaxor ferroelectrics. [22][23][24][25][26][27][28][29] Hybrid perovskites have attracted attention for their photovoltaic, ferroelectric, barocaloric and magnetic properties. [30][31][32][33][34][35] Such materials have the typical formula of ABX 3 of purely inorganic perovskites, but have organic molecular A-site cations or X-site anions; this enables great diversity in chemical composition because of the variety of molecular building blocks that can be incorporated.…”