%0 DATA
%A Yan-Zhen, Zheng
%A Marco, Evangelisti
%A Floriana, Tuna
%A Richard, E. P. Winpenny
%D 2016
%T Co–Ln Mixed-Metal Phosphonate Grids and Cages
as Molecular Magnetic Refrigerants
%U https://acs.figshare.com/articles/Co_Ln_Mixed_Metal_Phosphonate_Grids_and_Cages_as_Molecular_Magnetic_Refrigerants/2558458
%R 10.1021/ja208367k.s017
%2 https://ndownloader.figshare.com/files/4201534
%K Co 8Ln families
%K Co 6Ln
%K Co 4Ln families
%K 7 T
%K magnetocaloric effect
%K 3 K
%K Magnetic studies
%K metal centers
%K Co 4Ln
%K RefrigerantsThe synthesis
%K gadolinium derivatives
%K Co 4Gd
%K entropy changes
%K kg
%K MCE
%K Co 8Ln family
%K Co 6Gd
%X The synthesis, structures, and magnetic properties of
six families
of cobalt–lanthanide mixed-metal phosphonate complexes are
reported in this Article. These six families can be divided into two
structural types: grids, where the metal centers lie in a single plane,
and cages. The grids include [4 × 3] {Co_{8}Ln_{4}}, [3 × 3] {Co_{4}Ln_{6}}, and [2 × 2]
{Co_{4}Ln_{2}} families and a [4 × 4] {Co_{8}Ln_{8}} family where the central 2 × 2 square
is rotated with respect to the external square. The cages include
{Co_{6}Ln_{8}} and {Co_{8}Ln_{2}}
families. Magnetic studies have been performed for these compounds,
and for each family, the maximum magnetocaloric effect (MCE) has been
observed for the Ln = Gd derivative, with a smaller MCE for the compounds
containing magnetically anisotropic 4f-ions. The resulting entropy
changes of the gadolinium derivatives are (for 3 K and 7 T) 11.8 J
kg^{–1} K^{–1} for {Co_{8}Gd_{2}}; 20.0 J kg^{–1} K^{–1} for
{Co_{4}Gd_{2}}; 21.1 J kg^{–1} K^{–1} for {Co_{8}Gd_{4}}; 21.4 J kg^{–1} K^{–1} for {Co_{8}Gd_{8}}; 23.6 J kg^{–1} K^{–1} for {Co_{4}Gd_{6}}; and 28.6 J kg^{–1} K^{–1} for {Co_{6}Gd_{8}}, from which we can see these
values are proportional to the percentage of the gadolinium in the
core.