3 research outputs found
Gadolinium Sulfate Modified by Formate To Obtain Optimized Magneto-Caloric Effect
Three new Gd<sup>III</sup> based
coordination polymers [Gd<sub>2</sub>(C<sub>2</sub>H<sub>6</sub>SO)Â(SO<sub>4</sub>)<sub>3</sub>(H<sub>2</sub>O)<sub>2</sub>]<i><sub>n</sub></i> (<b>1</b>), {[Gd<sub>4</sub>Â(HCOO)<sub>2</sub>Â(SO<sub>4</sub>)<sub>5</sub>Â(H<sub>2</sub>O)<sub>6</sub>]·H<sub>2</sub>O}<i><sub>n</sub></i> (<b>2</b>), and [GdÂ(HCOO)Â(SO<sub>4</sub>)Â(H<sub>2</sub>O)]<i><sub>n</sub></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><sub>m</sub>) is. Complex <b>3</b> exhibits the largest
−Δ<i>S</i><sub>m</sub> = 49.91 J kg<sup>–1</sup> K<sup>–1</sup> (189.51 mJ cm<sup>–3</sup> K<sup>–1</sup>) 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-SnF<sub>2</sub> 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><sub>N</sub> 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-SnF<sub>2</sub> 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><sub>N</sub> 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>