Study of the relationship between magnetic field and dielectric properties in two ferromagnetic complexes

Abstract

By changing metal ions in the existing [guest][M^IIIM^II(HCOO)₆] framework, heterometallic formate frameworks formulated as [NH₂(CH₃)₂][Cr^IIIFe^II(HCOO)₆] (1) and [NH₂(CH₃)₂][Cr^IIINi^II(HCOO)₆] (2) were synthesized and characterized by single crystal X-ray diffraction, dielectric measurement and magnetic susceptibility measurement. Both complexes 1 and 2 exhibit long-range ferromagnetic ordering (LRO) at Curie temperatures of 15.3 (1) and 20.9 K (2) through ac magnetization susceptibility and zfc/fc measurements. Complex 1 possesses a hysteresis loop with H_c/M_r being 2.77 kOe/2.83 Nμ_B. Measurements on the dielectric properties of 1 and 2 show an apparent dielectric response. Interestingly, the dielectric constants can be increased under an applied magnetic field.