Slow Magnetic Relaxation of Ni(III) Complexes toward Molecular Spin Qubits
Keiga Toshima, Tetsu Sato, Yoji Horii, Kazunobu Sato, Kenji Sugisaki, Brian K. Breedlove, Shinya Takaishi, Zhao‐Yang Li, Masahiro Yamashita
Abstract
Abstract Molecule‐based magnetic materials are promising candidates for molecular spin qubits, which utilize spin relaxation behavior. Various kinds of transition metal complexes with S =1/2 have been reported to act as spin qubits with long spin‐spin relaxation times ( T 2 ). However, the spin qubit properties of low‐spin Ni(III) complexes are not as well known since Ni(III) compounds are often unstable. We report here the slow magnetic relaxation behavior and T 2 values for three kinds of low‐spin Ni(III) based complexes with S =1/2 under magnetically diluted conditions. [Ni(cyclam)X 2 ]Y (cyclam=1,4,8,11‐tetraazacyclotetradecane) with octahedral structures and [Ni(mnt) 2 ] − (mnt=maleonitriledithiolate) with a square‐planar structure underwent slow magnetic relaxations in the presence of a dc magnetic bias field. From electron spin resonance (ESR) spectroscopy, the Ni(III) complexes exhibited observable T 2 , indicating that Ni(III) complexes are promising candidates for use as molecule‐based spin qubits.