title: Synthesis, Structure, and Pressure-Induced Polymerization of Li3Fe(CN)6 Accompanied with Enhanced Conductivity.
abstract: Pressure-induced polymerization of charged triple-bond monomers like acetylide and cyanide could lead to formation of a conductive metal-carbon network composite, thus providing a new route to synthesize inorganic/organic conductors with tunable composition and properties. The industry application of this promising synthetic method is mainly limited by the reaction pressure needed, which is often too high to be reached for gram amounts of sample. Here we successfully synthesized highly conductive Li3Fe(CN)6 at maximum pressure around 5 GPa and used in situ diagnostic tools to follow the structural and functional transformations of the sample, including in situ X-ray and neutron diffraction and Raman and impedance spectroscopy, along with the neutron pair distribution function measurement on the recovered sample. The cyanide anions start to react around 1 GPa and bond to each other irreversibly at around 5 GPa, which are the lowest reaction pressures in all known metal cyanides and within the technologically achievable pressure range for industrial production. The conductivity of the polymer is above 10(-3) S · cm(-1), which reaches the range of conductive polymers. This investigation suggests that the pressure-induced polymerization route is practicable for synthesizing some types of functional conductive materials for industrial use, and further research like doping and heating can hence be motivated to synthesize novel materials under lower pressure and with better performances.
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Beijing, 100094, China.|Geophysical Laboratory, Carnegie Institution of Washington , Washington, District of Columbia 20015, United States.
authors.forename: Kuo
authors.initials: K
authors.lastname: Li
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Beijing, 100094, China.|Geophysical Laboratory, Carnegie Institution of Washington , Washington, District of Columbia 20015, United States.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Japan Proton Accelerator Research Complex Center, Japan Atomic Energy Agency , Tokai, Ibaraki 319-1195, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Hattori
authors.affiliation: Japan Proton Accelerator Research Complex Center, Japan Atomic Energy Agency , Tokai, Ibaraki 319-1195, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Sano-Furukawa
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Tulk
authors.forename: Jamie
authors.initials: J
authors.lastname: Molaison
authors.forename: Mikhail
authors.initials: M
authors.lastname: Feygenson
authors.forename: Ilia N
authors.initials: IN
authors.lastname: Ivanov
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Beijing, 100094, China.|HPSynC, Geophysical Laboratory, Carnegie Institution of Washington , Argonne, Illinois 60439, United States.
authors.forename: Wenge
authors.initials: W
authors.lastname: Yang
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Beijing, 100094, China.|Geophysical Laboratory, Carnegie Institution of Washington , Washington, District of Columbia 20015, United States.
authors.forename: Ho-Kwang
authors.initials: HK
authors.lastname: Mao