Organic-inorganic hybrid magnets, which are incorporated with organic molecules and inorganic fragments into a single crystalline lattice, evoke abundant fundamental physics and multifunction due to introducing the magnetism into organic-inorganic hybrid materials. However, the expected multifunctional applications of magnetic organic-inorganic hybrid materials are significantly limited by their magnetic ordering temperatures much lower than room temperature.

Prof. ZHANG Zhidong’s group at Institute of Metal Research, Chinese Academy of Sciences (IMR, CAS), designed and synthesized a type of new organic-inorganic hybrid material and showed the possibility of tuning the magnetic properties through synthesis, with international collaboratives. The main findings have been published on December 26, 2018 in Chemistry of Materials (doi:10.1021/acs.chemmater.8b04814).

It is found that a simple chemical solution method can synthesize room-temperature ferrimagnetic inorganic-organic hybrid nanomaterials built by organic Fe(teta)_1.5 and inorganic FeSe_x segments. An enhanced Fe content in the hybrid products with raising the reaction temperature revealed a diffusion mechanism of Fe³⁺ and/or Fe²⁺ into inorganic building units, which induced the evolution of morphology from nanoparticles and nanobelts to nanoplates. Controllably constructing well-defined inorganic and organic building units may enrich organic-inorganic hybrid family for future applications.

Thermal gravimetric analysis and in-situ high-temperature X-ray diffraction patterns of the as-synthetic tetragonal (β-Fe₃Se₄)₄[Fe(teta)_1.5] nanoplates show an excellent thermal stability. Magnetic measurements revealed the room-temperature ferrimagnetism of the (β-Fe₃Se₄)₄[Fe(teta)_1.5] nanoplates with a record-high Curie temperature more than 530 K. In the case of hybrid nanoplates synthesized at 483 K, a giant coercivity value reaching 11 kOe is obtained at 5 K.

This work is supported by the National Key R&D Program of China from the ministry of Science and Technology of China, the National Natural Science Foundation of China and Future Materials Discovery Program through the National Research Foundation of Korea.