Mn²⁺-Mn²⁺ Magnetic Coupling Effect on Photoluminescence Revealed by Photomagnetism in CsMnCl₃

The magnetic coupling interaction of Mn²⁺-Mn²⁺ in Mn²⁺-included phosphors could induce a shorter emission decay time, compared with that of isolated Mn²⁺, which could overcome the photoluminescence (PL) saturation when stimulated by a high photon flux due to the long lifetime of the Mn²⁺ excited state. However, few studies have directly proved the Mn²⁺-Mn²⁺ coupling effect on the PL decay. In this paper, the effect on PL of CsMnCl₃ (CMC) and its hydrates is revealed by photomagnetism results, excluding the interference effects of site symmetry and phonon energy. The antiferromagnetic interaction of the CMC is larger when Mn²⁺ at a photoexcited state than at a dark state, which is contrary to the hydrates with weak Mn²⁺-Mn²⁺ interaction. This research not only helps researchers to understand the fundamental optical process but also is instructive for designing high performance Mn²⁺-doped phosphors in the field of displays and lighting.