Pressure response of three-dimensional cyanide-bridged bimetallic magnets.
Effects of pressure on the structures and magnetic properties of three types of 3-D cyanide-bridged bimetallic coordination polymer magnets, MnIICrIII ferrimagnet [Mn(en)]3[Cr(CN)6]2.4H2O (1; en = ethylenediamine), NiIICrIII ferromagnet [Ni(dipn)]3[Cr(CN)6]2.3H2O (2; dipn = N,N-di(3-aminopropyl)amine), and NiIIFeIII ferromagnet [Ni(dipn)]2[Ni(dipn)(H2O)][Fe(CN)6]2.11H2O (3), were systematically examined under hydrostatic pressure up to 19.8 GPa using a piston-cylinder-type pressure cell and a diamond anvil cell. The ferrimagnet 1 showed the reversible crystalline-to-amorphous-like phase change, and the magnetic phase transition temperature (TC) was reversibly changed from 69 K at 0 GPa to 126 K at 4.7 GPa. At higher pressure, the net magnetization was suppressed with increasing pressure, and the magnetic state at 19.8 GPa was assumed to be paramagnetic. The initial ferrimagnetic phase of 1 was not recovered after releasing the pressure from 19.8 GPa. The magnetic phase of 2 was reversibly converted between ferromagnetic and paramagnetic-like phase in the range 0 </= P </= 4.7 GPa while maintaining its crystallinity. The porous ferromagnet 3 was easily amorphized and irreversibly lost the ferromagnetic phase under low pressure (P </= 1.0 GPa). The flexible cyanide-bridged magnetic frameworks demonstrate well the pressure response as a reflection of differences in the magnetic structure and the framework strength in the GPa range.
Ohba
Masaaki
M
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan. ohba@sbchem.kyoto-u.ac.jp
Kaneko
Wakako
W
Kitagawa
Susumu
S
Maeda
Takuho
T
Mito
Masaki
M
D002857:Chromium / Q000737:chemistry*; D003486:Cyanides / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D019216:Metals, Heavy / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D033362:Powder Diffraction; D011312:Pressure; D011437:Propylamines / Q000737:chemistry; D013696:Temperature
D003486:Cyanides; D008024:Ligands; D019216:Metals, Heavy; C528320:N,N-di(3-aminopropyl)amine; D009942:Organometallic Compounds; D011437:Propylamines; D002857:Chromium