Low-magnetic-field controlled magnetodielectric coupling at room temperature in a chiral layered diphenylalanine-based 1D-coordination-polymer

摘要

Materials with low-magnetic-field control at room temperature is of fundamental importance for the practical application. Herein, a chiral 1D-coordination-polymer ([Ni(DPA)(2)(H2O)]) possessing coupled ferroelectric and ferromagnetic order is constructed. In addition, [Ni(DPA)(2)(H2O)] exhibits room-temperature ferroelectricity with giant magnetodielectric coefficency between -18% and -23% in the temperature range from 270 to 310 K, in nearly all measured frequencies, and under applied magnetic field as low as 0.5 T. The asymmetrical distortion of the coordination bond spurs electrical polarization and magnetodielectric effect, and reduces spin frustration in the octahedral geometry due to spin-lattice coupling. In addition, 2D nanosheets with non-centrosymmetric structure can be successfully exfoliated from [Ni(DPA)(2)(H2O)] microcrystals in retaining the morphological and structural integrity. This observation reveal a new class of magnetodielectric material and represent an important step towards practical device applications using the magnetodielectric coupling by exploiting the asymmetrical distortion of coordination bonds in lead-free organic-inorganic coordination complex.