Synthesis and characterization of praseodymium-containing ZrSiO4 solid solutions from gels

Synthesis and characterization of (Pr, Ce)‐ZrSiO4 ceramic pigments: The properties of the pigments and the effect of Ce

“…In the case of Pr, it was difficult to determine its valence state using the XPS spectra since the main Pr 3+ peaks in the XPS spectra overlap with those of Pr 4+ . Hence, the valence states of Pr were inferred based on the UV‐VIS‐NIR absorption spectra presented in Figure B . All of the samples contained a certain amount of Pr 3+ , since they all exhibited an absorption band at approximately 590 nm, which results from the 3 H 4 → 1 D 2 transition and is exclusively ascribed to Pr 3+ cations .…”

“…Hence, the valence states of Pr were inferred based on the UV‐VIS‐NIR absorption spectra presented in Figure B . All of the samples contained a certain amount of Pr 3+ , since they all exhibited an absorption band at approximately 590 nm, which results from the 3 H 4 → 1 D 2 transition and is exclusively ascribed to Pr 3+ cations . It is worth noting that, in samples P6C0 to P6C9, the intensity of the absorption band at approximately 590 nm gradually decreased.…”

“…The mechanism underlying the formation of Pr‐ZrSiO 4 , the locations of Pr, as well as its valence states, and the types and uses of mineralizer have been studied in detail by many researchers. The reported methods of synthesis for Pr‐ZrSiO 4 pigment include solid‐state reaction, sol‐gel, nonhydrolytic sol‐gel and hydrothermal methods . However, commercial Pr‐ZrSiO 4 pigment is mainly prepared using the conventional solid‐state reaction method due to its convenience and the low levels of pollution that it emits.…”

“…Therefore, it is necessary to determine how to improve or maintain the color intensity of Pr‐ZrSiO 4 pigment. In addition, the Pr‐ZrSiO 4 pigment synthesized using either the conventional method or other methods often has a weak green tone, which can result in Pr‐ZrSiO 4 pigment with a cold tone; this is to be avoided, since a pleasantly warm tone is more popular than a cold tone in the ceramic decoration market.…”

Microstructural Evolution from Praseodymium‐Containing Zircon Gels to Prx‐ZrSiO4 Solid Solutions

“…In particular, structural and chemical concerns such as: the chemical state of Pr cations, i.e., as Pr 4+ and/or Pr 3+ , in the final zircon materials; the distribution of Pr cations in the available structural sites into the zircon structure; and the limit of solubility of Pr into the structure, i.e., the amount of Pr cation inside the zircon structure, are still studied. In a recent article we have reported results on the structural and chemical changes that occurred on annealing mineralizer‐free Pr‐ZrSiO 4 gels over the range of temperature up to formation of zircon . The variation of lattice parameters and the diffuse reflectance spectra of final Pr‐containing ZrSiO 4 crystalline phases indicated the formation of a series of solid solutions in which Zr 4+ was replaced by Pr 4+ in dodecahedral sites of zircon structure.…”