A semiconducting layered metal-organic framework magnet.

Yang, Chongqing; Dong, Renhao; Wang, Mao; Petkov, Petko St; Zhang, Zhitao; Wang, Mingchao; Han, Peng; Ballabio, Marco et al. · Nat Commun · 2019

basic_science · Level V

Where this comes from

Abstract

The realization of ferromagnetism in semiconductors is an attractive avenue for the development of spintronic applications. Here, we report a semiconducting layered metal-organic framework (MOF), namely K<sub>3</sub>Fe<sub>2</sub>[(2,3,9,10,16,17,23,24-octahydroxy phthalocyaninato)Fe] (K<sub>3</sub>Fe<sub>2</sub>[PcFe-O<sub>8</sub>]) with spontaneous magnetization. This layered MOF features in-plane full π-d conjugation and exhibits semiconducting behavior with a room temperature carrier mobility of 15 ± 2 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup> as determined by time-resolved Terahertz spectroscopy. Magnetization experiments and <sup>57</sup>Fe Mössbauer spectroscopy demonstrate the presence of long-range magnetic correlations in K<sub>3</sub>Fe<sub>2</sub>[PcFe-O<sub>8</sub>] arising from the magnetic coupling between iron centers via delocalized π electrons. The sample exhibits superparamagnetic features due to a distribution of crystal size and possesses magnetic hysteresis up to 350 K. Our work sets the stage for the development of spintronic materials exploiting magnetic MOF semiconductors.