Li$_2$MnCl$_4$ single crystal: new candidate for red-emitting neutron scintillator

• Main Authors: Vanecek, Vojtech, Kral, Robert, Krehlikova, Katerina, Kuverkova, Romana, Babin, Vladimir, Zemenova, Petra, Rohlicek, Jan, Malkova, Zuzana, Jurkovicova, Terezia, Nikl, Martin
• Format: Journal Article
• Language: English
• Published: 28-08-2024
• Subjects: Physics - Instrumentation and Detectors; Physics - Materials Science
• DOI: 10.48550/arxiv.2408.16178

Novel red-emitting scintillator Li$_2$MnCl$_4$ is proposed as a candidate for
thermal neutron detection. It features high Li content, low density, low
effective atomic number, and emission in red-NIR region. These characteristics
make it an interesting candidate for long distance neutron detection in harsh
enviroments e. g. decomisioning of nuclear powerplants. The absorption spectrum
is thoroughly investigated in the scope of Tanabe-Sugano diagram. Luminescence
mechanism in the undoped Li$_2$MnCl$_4$ is studied in depth. Doping by
Eu$^{2+}$ and Ce$^{3+}$ is introduced as a trial to improve the scintillation
efficiency. We show in the Eu$^{2+}$ and Ce$^{3+}$ doped Li$_2$MnCl$_4$ that
luminescence mechanism involves energy transfer from the dopants to Mn$^{2+}$,
and propose the local lattice distortion around the dopant and a possible
charge compensation mechanisms.