Emergent magnetism from lithium freezing in lithium-doped boron nitride

Abstract

The synthesis and characterization of Li-doped boron nitride is reported where the sample is in the dilute limit with a stoichiometry of Li-0.01(BN)(3). The diffusion of atomic Li dominates above 150 K, with D-Li similar to 10(-10) cm(2)s(-1), where the Li diffusion rate increases with temperature resulting in activated behavior with an energy scale of 27 meV. Below 150 K the Li diffusion freezes out and the sample enters a magnetic state at approximately 70 K that shows evidence for being glassy in nature. It is believed that this is due to the freezing of Li atoms within the lattice which then involves partial electron injection into the BN layers, and this provides a mechanism for magnetic exchange, resulting in a divergence of the magnetic susceptibility. Our work shows the promise of this material for future study, where there is currently much interest in Li base compounds for energy storage.