Lithium Rare-Earth Fluorides As Photonic Materials: 1. Physicochemical Characterization

LiRF4 lithium rare-earth (RE) fluorides existing in the LiF–RF3 systems are important laser materials. This review examines phase equilibria in the LiF–RF3 systems, the structure of the LiRF4 compounds, and distinctive features of the melt growth of single crystals of the compounds. Data on impurity distribution coefficients are analyzed and general analytical dependences are proposed for the RE series. We consider the use of the LiF–RF3 systems for synthesis of other functional materials and present information about compounds existing in ternary systems containing lithium and RE fluorides and about LiRF4-based nano- and micromaterials.