Phase Diagram and Microstructure in the ZnO–Pr₂O₃ System

Abstract

The phase diagram of the ZnO–Pr2O3 system with PrO1.83 contents from 0.5 to 98 mol% was studied via differential thermal analysis (DTA). The system ZnOPr2O3 showed a simple eutectic type of phase diagram with no solid solutions and no other compounds. The eutectic temperature was determined to be 1382 ± 5°C. The liquidus line near the eutectic point was determined by a quenching method.

Atomic-scale segregation behavior of Pr at a ZnO [0001]Σ49tilt grain boundary

“…It is considered that Pr-doped ZnO crystal bulk has a relatively unstable structure because solid solubility of Pr into ZnO is fairly low. 13 Figure 4͑k͒ shows the VCDP along Pr-O bonds at the Pr-doped ZnO ⌺7 GB. There is also a similar tendency that VCDPs along Pr-O bonds at the ZnO ⌺7 GB, when compared with those in Pr-doped ZnO crystal bulk, became closer to those of stable Pr 2 O 3 crystals bulk.…”

“…The other one is a cubic structure, which is called "C-type" Pr 2 O 3 . Besides, according to the reported phase diagram, 13 ZnO-Pr 2 O 3 system showed eutectic type phase diagram, and there were no other compounds composed of Zn, Pr, and O. Thus, A-type and C-type Pr 2 O 3 were chosen for stable Pr 2 O 3 crystal phases in this study.…”

Nanocrystalline Pr-doped ZnO insulator for metal–insulator–Si Schottky diodes

“…The state diagram of ZnO-Pr 2 O 3 system was studied in Ref. [13], where established that it is a simple eutectic type with no solid solutions and no other compounds, i.e. the solubility of Pr in ZnO is very little.…”

Segregation and properties at curved vs straight (000) inversion boundaries in piezotronic ZnO bicrystals

“…Therefore, the segregation behavior of varistor forming dopants such as Bi and Pr at such boundaries is of particular interest. In contrast with the transition element dopants commonly used, bismuth and praseodymium are virtually insoluble in ZnO, which can readily be explained by their much larger atomic and ionic radii compared to zinc. In consequence, they segregate to grain boundaries and triple junctions in polycrystalline ceramics .…”