Influence of Homogenization and Micro/Nano Source of Starting Powders on Format Ion of the Single YAP Phase

Abstract

Manufacturing high purity polycrystalline YAlO3 (YAP) ceramics could replace monocrystalline YAP thus recently it is an interesting task for low cost producers of scintillators. The paper presents influence of different source of initial oxide powders (micro/nano powders of Y2O3 and Al2O3) and the method of their homogenization on the formation of a YAP phase. The solid state reaction method was used to prepare YAP powder or ceramic pellets. After preheating, all samples in the form of powders and pellets were heat-treated in the temperature range of 1050-1650 °C. DTA method was applied for examination of the phase crystallization in the tested system. X-ray diffraction method (XRD) was used for characterization of the phase composition. X-ray microanalysis (EDS) was used to control homogeneity in the small areas. Morphology of the resultant samples are presented on SEM pictures. The results show a significant influence of the starting powders on the homogeneity, purity and temperature of formation of the main phase.

Optical and structural properties of europium doped Y–Al–O compounds grown by microwave driven hydrothermal technique

“…Microwave driven hydrothermal reactor enables carrying out the reaction with simultaneous control of the power reflected from the reaction mixture in the vessel. In addition, the reaction temperature and pressure can be controlled in the reactor, so the reaction can be reproducible [21,22].…”

“…Figures [19][20][21] present excitation spectra at emission wavelength (λ em ) 610 nm for samples obtained by hydrothermal method at pH=10, 12 and 14, respectively.…”

“…Polycrystalline yttrium-based oxides, doped with RE are promising materials for many applications, in particular optics and optoelectronics [7][8][9]. There are many phases in the equilibrium binary Y 2 O 3 -Al 2 O 3 system: yttrium aluminum perovskite YAlO 3 (YAP), yttrium aluminum monoclinic Y 4 Al 2 O 9 (YAM), well-known and widely used as a phosphor or scintillator yttrium aluminum garnet Y 3 Al 5 O 12 (YAG) and it is hexagonal modification (YAH) [7,8].…”