Journal Article

Li2MnCl4 for neutron detection: tailoring red emission via doping

Vaněček, V, Kučerková, R, Babin, V, Nikl, M, Rubešová, K, Král, R, Křehlíková, K, Průša, P, Rohlíček, J

2025

Overview

In this work, we report on the growth of red-emitting lithium manganese(II) chloride (Li2MnCl4, LMC), a potential candidate for thermal neutron detection. The doping of Li2MnCl4 was proposed to optimize scintillation efficiency and three single crystals of Li2MnCl4:Sm2+, Li2MnCl4:Ti3+, and Li2MnCl4:In+ were grown by miniaturized vertical Bridgman method (mVB). While crystal growth was successful, the results from optical measurements indicated limited achievement in the optimization of luminescence properties. Ti3+ incorporation into the Li2MnCl4 lattice was highly uncertain, as neither the absorbance data nor the radioluminescence (RL) spectrum exhibited bands corresponding to the Ti3+ 2E → 2T2 radiative transition. In the case of Sm2+- and In+_doping, the RL efficiencies achieved only 3.39 and 2.14% of the bismuth germanate (Bi4Ge3O12, BGO) reference sample, respectively. Since the Li2MnCl4:Sm2+ photoluminescence (PL) spectra revealed line emissions corresponding to the Sm2+ forbidden 4f6 → 4f6 transitions, the temperature-dependent PL was measured. At higher temperatures (specifically, from 437 K), the broad emission of the 4f55d → 4f6 transition dominated, which indicated the thermal population of the 5d state.

• Publisher: IOP Publishing
• Subject: BGO (crystal) / Bridgman method / Crystal growth / Doping / Line spectra / Lithium / Luminescence / Optical measurement / Optical properties / Optimization / Photoluminescence / Single crystals / Temperature dependence / Thermal neutrons