Extremely low-frequency phonon material and its temperature- and photo-induced switching effects

Abstract

Extremely low-frequency optical phonon mode in Rb-intercalated two-dimensional cyanide-bridged Co–W bimetal assembly and its temperature- and photo-induced switching effect.

Development of Nd (III)-Based Terahertz Absorbers Revealing Temperature Dependent Near-Infrared Luminescence

“…Notably, this effect contradicts the previous observations of blueshift in THz-TDS signals noted for 3D A I x Cu II 7 [Mo IV (CN) 8 ] 3.5 + x/4 ·nH 2 O networks [ 21 ]. Concurrently, it agrees with the redshift for A I [Co II (3-CNpy) 2 ] [W V (CN) 8 ] layered material [ 22 ]. Moreover, the influence of factors other than the molecular weight of constituent atoms cannot be ruled out, and this requires further research.…”

“…At 10 K, 3 sharp peaks were observed around 0.68 THz (22.7 cm −1 ), 0.77 THz (25.7 cm −1 ), and 0.96 THz (32.0 cm −1 ) for 1-S , and 0.62 THz (20.7 cm −1 ), 0.78 THz (26.0 cm −1 ), and 0.97 THz (32.3 cm −1 ) for 1-Se . A similar peak width reduction effect upon cooling was previously observed for the coordination polymer Rb I [Co II (3-CNpy) 2 ] [W V (CN) 8 ], where 3-CNpy = 3-cyanopyridine [ 22 ]. In addition, the lowest energy peak in the sub-THz region, associated with the phonon mode of the Rb + ion, revealed a blueshift during cooling below 150 K. Most probably, the blueshift is linked with the volume reduction in the crystal structure; however, this statement could not be unequivocally concluded based on the previously obtained results for Rb I [Co II (3-CNpy) 2 ] [W V (CN) 8 ], due to the occurrence of a phase transition in this material.…”

“…Molecular materials are attractive to researchers due to their simple structures and predisposition to integrate various properties, such as magnetism [ 1 , 2 , 3 , 4 ] (e.g., long-range magnetic ordering [ 5 , 6 , 7 , 8 , 9 ], spin crossover [ 10 ], etc. ), sorption [ 11 , 12 , 13 ], luminescence [ 14 , 15 ], conductivity [ 16 , 17 ], non-linear optics [ 18 , 19 , 20 ], and low frequency absorbing capability [ 21 , 22 , 23 ]. The judicious selection of building blocks and their arrangements in solid-state structures results in the desired behaviors of molecular origin.…”

“…Notably, a limited number of studies on the THz-TDS and LF-Raman spectroscopies of Ln (III)-based assemblies and other transition metal compounds have been conducted [ 47 , 48 , 49 ]. Until now, only one strategy for producing sub-THz absorbing materials has been identified by utilizing heavy alkali metal ions (i.e., Rb + and Cs + ) trapped inside cyanido-bridged coordination polymers [ 21 , 22 , 23 ]. However, this method has limitations, due to the necessity to design a material based on a high-dimensional coordination polymer containing heavy ions, which is difficult to achieve for this class of materials [ 50 ].…”

Engineering of the XY Magnetic Layered System with Adeninium Cations: Monocrystalline Angle-Resolved Studies of Nonlinear Magnetic Susceptibility

“…Such an approach has been widely employed to achieve a diversity of spin-crossover (SCO) transitions in Hofmann-type M­[M′(CN) 4 ] (M = Fe II ; M′ = Ni II , Pd II , and Pt II ) clathrates, − implementation of various additional functions into layered oxalates {M­[M′(C 2 O 4 ) 3 ]} 0/– − or anilates {M­[M′(C 6 O 4 X 2 ) 3 ]} − − (M, M′ = divalent or trivalent 3d metal ions), engineering of interlayer separation and long-range magnetic ordering (LRMO) in hybrid layered hydroxides, , tuning of LRMO in thiocyanato-bridged solid solutions [Co x Ni 1– x (NCS) 2 (ligand) 2 ] n , or the very recent electrochemical modification of interlayer nanospace in newly established Cr­(pyrazine) family. , A significant contribution to the field is provided by cyanide-bridged networks with recurrent modular 2D bimetallic backbones MM′· ligand · guest involving exchangeable [M′(CN) 8 ] 3–/4– (M′ = Mo, W, Re, and Nb) and di- or trivalent 3d metal ions (Mn, Fe, Co, Ni, and Cu), or trivalent 4f ions, M . Various combinations of components did operate within a limited number of topologies to shape LRMO and its anisotropy, − which was frequently accompanied by externally controlled change in solvate/guest composition, , charge transfer and spin transition phenomena, − and charge carrier injection/extraction , or flow , phenomena.…”