The investigation of YAlO3-NdAlO3 system, synthesis and characterization

TL;DR

This study explores the phase diagram, synthesis, and characterization of YAlO3-NdAlO3 system, revealing high mutual solubility, a miscibility gap, and the growth of homogeneous crystals from the melt.

Contribution

It provides new insights into the phase behavior and synthesis methods of YAlO3-NdAlO3, including the determination of the phase diagram and crystal growth techniques.

Findings

High mutual solubility >25% in solid phase

Presence of a miscibility gap for intermediate compositions

Successful growth of homogeneous crystals from melt

Abstract

The binary phase diagram of the YAlO3 (YAP) - NdAlO3 (NAP) system was determined by differential thermal analysis (DTA) and X-ray powder diffraction (XRD) measurements. High purity nanocrystalline powders and small single crystals of Y_{1-x}Nd_{x}AlO_3 (0 \leq x \leq 1) have been produced successfully by modified sol-gel (Pechini) and micro-pulling-down methods, respectively. Both end members show high mutual solubility >25% in the solid phase, with a miscibility gap for intermediate compositions. A solid solution with x \approx 0.2 melts azeotropic ca. 20 degrees below pure YAP. Such crystals can be grown from the melt without segregation. The narrow solid/liquid region near the azeotrope point could be measured with a "cycling" DTA measurement technique.