1 research outputs found
In-Situ Observation of Phase Separation During Growth of Cs<sub>2</sub>LiLaBr<sub>6</sub>:Ce Crystals Using Energy-Resolved Neutron Imaging
In-situ
imaging and characterization of Cs<sub>2</sub>LiLaBr<sub>6</sub>:Ce
crystal growth are performed utilizing energy-resolved
neutron imaging. The unique capability of neutrons to penetrate the
furnace and to provide direct information on the materials within
the furnace is used to visualize the growth dynamics, location, and
shape of the liquid/solid interface and to map the elemental composition.
Nontrivial dynamics of phase separation within the liquid and solid
phases were observed and investigated. Quantitative projected two-dimensional
maps of Li concentrations were obtained with sub-millimeter spatial
resolution delineating Li-rich and Li-depleted areas. Concurrent variations
in Cs and Br concentrations were identified. Good transparency was
obtained in part of the ingot where the liquid phase separation has
reached steady state, suggesting that nonstoichiometric materials
may be optimal for the original charge. The results demonstrate that
energy-resolved neutron imaging and its associated modalities can
provide unique information for the optimization of crystal growth
conditions, in particular having the potential to accelerate scale-up
from laboratory to commercial production by improving the yield and
quality of single crystal materials