Spectroscopic and crystallographic studies of YAG:Pr4+ single crystals

Electrochemical characterization of praseodymium centers in Pr x Zr1−x O2 zirconias using electrocatalysis and photoelectrocatalysis

“…In fact, the widely used industrially yellow ceramic pigment Pr x Zr 1-y Si 1-z O 4 (y + z = x) is a solid solution of Pr 4+ in the zircon host lattice as it has been proved by different authors [45]. Recently, Pawlak et al [14] reported absorption bands in the 430-500-, 570-620-, and 960-1,040-nm regions for (Y 1−x-y Pr x Mg y ) 3 Al 5 O 12 (x = 0.012, y = 5 x 10 −6 ) materials annealed in oxidizing (air) or reducing atmospheres (hydrogen/nitrogen). The spectra of both samples exhibited the characteristic absorption lines of Pr 3+ .…”

“…Recently, some reports on Pr x Zr 1−x O 2 materials deal with the synthesis and X-ray powder diffraction (XRD) characterization of doped zirconia crystalline forms [10] and the spectral characteristics of monoclinic and tetragonal Pr x Zr 1−x O 2 [11][12][13][14]. Although it is frequently assumed that praseodymium acts as a typical trivalent rare earth element, it is possible to expect that this element can also exhibit a +4 oxidation state when stabilized in zirconia host.…”

“…In fact, it is known that at low temperatures praesodymia, by itself, can form a wide range of ordered intermediate phases between PrO 2 and Pr 2 O 3 [15], with a structural chemistry similar to that of ceria [16]. Thus, Pawlak et al [14] have reported that Pr 4+ can be stabilized in Pr plus Mgcodoped ytrium-aluminum-garnet, a widely used material for solid-state lasers, after annealing the material in a relatively oxidizing atmosphere (air) on the basis of the spectral characteristics of (Y 1−x-y Pr x Mg y ) 3 Al 5 O 12 (x = 0.012, y = 5 x 10 −6 ) materials.…”

Can Pr-Doped YAP Scintillator Perform Better?

“…It was reported that absorption bands around 2.1-2.3 eV and 3.1-3.3 eV can be related to the O -based hole centers in YAP structure [29], [30]. At the same time the latter band can be also related to charge transfer transition from the valence band (oxygen ligands) towards Pr center [31], [32].…”

Electronic structure of Prx La1‐xAlO3 solid solution

“…LaAlO 3 crystal has a phase transition from high-temperature cubic phase to low-temperature rhombohedral phase at temperature of 830 K. The phase transition of LaAlO 3 generates micro-twins, ferroelastic domains, a rough surface and lateral distortions. The crystals of Pr x La 1−x AlO 3 solid solution grown by the Czochralski method [6] have different coloration: dark brown colour is probably a result of presence of Pr 4+ ions [1,7,8], light green colour is typical for Pr 3+ ions and brownish-red coloration especially in LaAlO 3 crystal is probably due to the colour centres [9]. Recently, the X-ray photoelectron spectroscopy (XPS) was used to study the electronic structure of PrAlO 3 single crystals before and after thermal treatment [10].…”