Gadolinium Sulfate Modified by Formate To Obtain Optimized Magneto-Caloric Effect

Three new Gd^III based coordination polymers [Gd₂(C₂H₆SO)­(SO₄)₃(H₂O)₂]<i>_n</i> (<b>1</b>), {[Gd₄­(HCOO)₂­(SO₄)₅­(H₂O)₆]·H₂O}<i>_n</i> (<b>2</b>), and [Gd­(HCOO)­(SO₄)­(H₂O)]<i>_n</i> (<b>3</b>) were obtained by modifying gadolinium sulfate. With the gradual increase of the volume ratio of HCOOH and DMSO in synthesis, the formate anions begin to coordinate with metal centers; this results in the coordination numbers of sulfate anion increasing and the contents of water and DMSO molecules decreasing in target complexes. Accordingly, spin densities both per mass and per volume were enhanced step by step, which are beneficial for the magneto-caloric effect (MCE). Magnetic studies reveal that with the more formate anions present, the larger the negative value of magnetic entropy change (−Δ<i>S</i>_m) is. Complex <b>3</b> exhibits the largest −Δ<i>S</i>_m = 49.91 J kg^–1 K^–1 (189.51 mJ cm^–3 K^–1) for <i>T</i> = 2 K and Δ<i>H</i> = 7 T among three new complexes

Design and Synthesis of Stable Cobalt-Based Weak Ferromagnetic Framework with Large Spin Canting Angle

It still remains a great challenge to design and construct framework-structured weak ferromagnets with large canting angle which is an effective approach for high performance magnets. According to the strategy of antisymmetric interaction causing spin canting, we report the design of four cobalt compounds, which were tested by X-ray single crystal diffraction, TGA, PXRD, and magnetic measurement. Single-crystal structure analysis reveals that compound <b>1</b> has a 2D structure, complex <b>2</b> has a 3,4-connected 3D framework, and complex <b>3</b> exhibits a 3D net structure with rare 3,5-connected 2-nodal β-SnF₂ topology and the solvent MeOH trapped in the 3D channels as guests. The magnetic property of <b>3</b> is spin canting just as designed, with <i>T</i>_N about 4.0 K and large canting angle of 14.8°. Highly stable compound <b>3</b> sustains its framework in air for more than 12 months, in which the guest MeOH molecules can be replaced by water to form complex <b>4</b>

Design and Synthesis of Stable Cobalt-Based Weak Ferromagnetic Framework with Large Spin Canting Angle

It still remains a great challenge to design and construct framework-structured weak ferromagnets with large canting angle which is an effective approach for high performance magnets. According to the strategy of antisymmetric interaction causing spin canting, we report the design of four cobalt compounds, which were tested by X-ray single crystal diffraction, TGA, PXRD, and magnetic measurement. Single-crystal structure analysis reveals that compound <b>1</b> has a 2D structure, complex <b>2</b> has a 3,4-connected 3D framework, and complex <b>3</b> exhibits a 3D net structure with rare 3,5-connected 2-nodal β-SnF₂ topology and the solvent MeOH trapped in the 3D channels as guests. The magnetic property of <b>3</b> is spin canting just as designed, with <i>T</i>_N about 4.0 K and large canting angle of 14.8°. Highly stable compound <b>3</b> sustains its framework in air for more than 12 months, in which the guest MeOH molecules can be replaced by water to form complex <b>4</b>