  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.
