Synthesis and optical properties of intense blue colors oxides based on Mn5+ in tetrahedral sites in Ba7Al2-Mn O10+

Understanding the Efficiency of Mn4+ Phosphors: Study of the Spinel Mg2Ti1–xMnxO4

“…Therefore, a thorough characterization of manganese ions formed in Mg 2 TiO 4 results crucial given that Mn 2+ , Mn 3+ , or Mn 5+ are all optically active ions, and their presence can significantly affect the photoluminescence (PL) properties of Mn 4+ and thus the phosphor itself. One advantageous characteristic of manganese ions is the rich peak structure shown by the corresponding excitation/absorption spectra associated with the manifold states arising from the d n ( n = 2–6) , configurations in their different valence states, making it important to identify them by optical spectroscopy. ,− Figure shows the reflectance spectra of Mg 2 TiO 4 singly doped with Mn and triply doped with Mn, Bi, and Li. Interestingly, there is a rich band structure below the host-material band gap (4 eV), being characteristic of the manganese valence state.…”

Synthesis, some Physicochemical and Biomedical Properties of colored Apatite‐Structured Compounds with Mn5+ and Cr5+

“…[15][16][17][18][19][20] Compounds of a different structural type, containing Mn 5 + in tetrahedral coordination and serving as potential candidates for non-toxic pigments and luminescent materials for bioimaging, have also been reported. [21][22][23][24][25][26][27] In the literature, Mn 5 + is most commonly encountered in compounds with Ba since it stabilizes manganese in tetrahedral coordination due to its high basicity (first ionization potential is 5.2 eV) and enhances the covalent character of the MnÀ O bond. [15,16,28,29] Ca and Sr, with ionization potentials of 6.1 and 5.7 eV, respectively, are expected to play a similar role in stabilizing Mn with an unusual oxidation state.…”

“…Compounds with an apatite structure containing Mn 5+ coordinated by tetrahedrally coordinated oxygen atoms can be promising materials for producing pigments [15–20] . Compounds of a different structural type, containing Mn 5+ in tetrahedral coordination and serving as potential candidates for non‐toxic pigments and luminescent materials for bioimaging, have also been reported [21–27] …”

Synthesis and Optical Properties Based on Ni-Doped Zn2SiO4 Blue Pigments with High-NIR Reflectance

“…Currently, the primary chromophoric ion responsible for blue coloration is Co 2+ . However, Co 2+ is expensive and environmentally polluting. − Previous research results show that when Ni 2+ , Cu 2+ , and Mn 5+ are in the tetrahedral coordination environment, a blue hue is possibly produced. − However, it is important to note that Mn 5+ ions are inherently unstable and prone to disproportionate to Mn 7+ and Mn 4+ . In the case of Ni 2+ , previous research has effectively produced various blue hues by Ni 2+ doping in regular tetrahedral coordination in structures such as CaAl 12 O 19 , BaAl 12 O 19 , MgAl 2 O 4 , and so on.…”