Diamagnetic Carrier-Doping-Induced Continuous Electronic and Magnetic Crossover in One-Dimensional Coordination Polymers
Yongbing Shen, Mengxing Cui, Guanping Li, Olaf Stefańczyk, Nobuto Funakoshi, Tomu Otake, Shinya Takaishi, Masahiro Yamashita, Shin‐ichi Ohkoshi
Abstract
The potential to introduce tunable electrical conductivity and molecular magnetism through carrier doping in metal–organic coordination polymers is particularly promising for nanoelectronics applications. Precise control of the doping level is essential for determining the electronic and magnetic properties. In this study, we present a series of one-dimensional coordination polymers, {(HNEt 3 ) 0.5 [Cu x Co (1– x ) (L)]} n (HNEt 3 = triethylammonium, L = 1,2,4,5-tetrakis(methanesulfonamido)benzene), doped with diamagnetic Cu 1+ carriers. Through comprehensive characterization of the structural, optical, and magnetic properties, we observed continuous electronic and magnetic crossover as the doping level was gradually increased. When x < 0.5, the doped compounds exhibit ferromagnetic insulating behavior with very high energy barriers ( U eff up to 560 K) and excellent slow relaxation of magnetization. At x = 0.5, {(HNEt 3 ) 0.5 [Cu 0.5 Co 0.5 (L)]} n functions as a paramagnetic semiconductor at high temperatures and a single-molecule magnet at low temperatures. When x > 0.5, the doped compounds act as diluted antiferromagnetic semiconductors with narrow band gaps ( E a = 0.2 eV). The emergence of such rich electronic and magnetic crossovers is ascribed to the cooperation of the strong electron-donating ability of the ligand and the pronounced crystal-field effects. Our findings indicate that one-dimensional (1D) coordination polymers are promising for the design of novel low-dimensional magnetic semiconductors.