Correlation between Segregation of Rare Earth Dopants in Melt Crystal Growth and Ceramic Processing for Optical Applications

Abstract

The paper deals with segregation of rare earth doping cations in solid-state hosts. Increased concentration of Ce3+ and Nd3+ on the grain boundaries of transparent garnet optical ceramics was recently reported. These experimental results correlate well with low segregation coefficients of Ce3+ and Nd3+ large rare earth cations and the higher segregation coefficients for small rare earth cations like Yb3+ in the garnet structure observed in the melt crystal growth and thin film liquid phase epitaxy from flux. Thus, the segregation in solid-state grain growth is qualitatively similar to that observed in the melt/flux growth of the garnet single crystals. The data on segregation in the melt/flux crystal growth are widely available and can be used for preliminary estimation of the dopant distribution in the ceramics produced from the solid state. This information could help to predict distribution of doping cations in the solid state hosts that is important in development of uniform and highly efficient optical materials.

Nd3+-doped Lu2O3 transparent sesquioxide ceramics elaborated by the Spark Plasma Sintering (SPS) method. Part 1: Structural, thermal conductivity and spectroscopic characterization

“…All our previous experimental results correlate well with low segregation coefficients of Ce 3+ and Nd 3+ large rare earth cations in the garnet structure, but higher segregation coefficients for small rare earth cations like Yb 3+ in the garnet and sesquioxide structures [20]. These segregation coefficients of Nd 3+ in YAG ceramics are: Ce 3+ (0.08), Nd 3+ …”

Wet‐Route Synthesis and Characterization of Yb:CaF2 Optical Ceramics

“…12,[20][21][22] The TEM observations that are presented in this paper confirm that the ytterbium concentration is higher at the grain boundary. The Fig.…”

Transparent Ceramics

“…More recently, a nanocrystalline spinel ceramics with 50 % increase in hardness was reported [222]. It is well known that mechanical strengthening by grain refinement is a method, i.e., the strength and hardness of a material can be increased by decreasing its grain size, as described by the empirical Hall-Petch relationship, which provided a guidance to produce stronger materials.…”