Retracted: Studies on the luminescence properties of cerium co‐doping on Ca₂MgSi₂O₇:Eu²⁺ phosphor by solid‐state reaction method

Abstract

Ca2MgSi2O7:Ce3+, Ca2MgSi2O7:Eu2+ and Ca2MgSi2O7:Eu2+,Ce3+ phosphors were prepared using the solid‐state reaction method. The crystal structures of the sintered phosphors were of melilite type, which has a tetragonal crystallography. The chemical compositions of the sintered phosphors was confirmed by energy dispersive X‐ray spectroscopy. The different thermoluminescence kinetic parameters [activation energy (E), frequency factor (s) and order of the kinetics (b)] of these phosphors were evaluated and compared using the peak shape method. Under ultraviolet excitation, the emission spectra of both Ca2MgSi2O7:Eu2+ and Ca2MgSi2O7:Eu2+,Ce3+ phosphors were composed of a broad emission band peaking at 530 nm. When the Ca2MgSi2O7:Eu2+ phosphor is co‐doped with Ce3+ ions, photoluminescence, afterglow and mechanoluminescence intensity was strongly enhanced. Ca2MgSi2O7:Eu2+ showed some afterglow with a short persist time. On incorporation of Ce3+, efficient energy transfer from Ce3+ to Eu2+ was found and the emission intensity of Eu2+ was enhanced. The mechanoluminescence intensities of Ca2MgSi2O7:Ce3+, Ca2MgSi2O7:Eu2+ and Ca2MgSi2O7:Eu2+,Ce3+ phosphors increased proportionally increased with the increase in impact velocity, which suggests that these phosphors can be used as sensors to detect stress in an object.

Red-Emitting Phosphor Ca2MgSi2O7: Sm3+, Eu3+ for UV White Light-Emitting Diodes

“…The decline in radius r yields a decreased crystal plane spacing d, which shifts the strongest diffraction peak in the high-angle direction. 9 . The Ca atoms are interspersed with these groups and are closely packed together to form a highly dense skeleton.…”

“…In addition, Si and O are connected to form form SiO 4 tetrahedra, Mg and O are connected to form MgO 4 tetrahedra, and the two tetrahedra are connected by sharing an O atom to form the (Si/Mg) O 7 group (Fig. (2c)); The average M-O distances are 1.916 Å (M=Mg) and 1.624 Å (M=Si), on average9 . The Ca atoms are interspersed with these groups and are closely packed together to form a highly dense skeleton.…”

Trap-regulated highly efficient mechanoluminescence and persistent mechanoluminescence of Ca2MgSi2O7:Eu2+

“…1c; it has a tetragonal melilite-type and non-centrosymmetric crystal structure. 39,40 There are two sites of Ca 2+ , which are sixcoordinated and eight-coordinated, respectively. 41 Comparison of the ionic radii of Ca 2+ (CN 6 = 1.00 Å, CN 8 = 1.12 Å), Mg 2+ (CN 6 = 0.72 Å, CN 8 = 0.89 Å), Si 2+ (CN 4 = 0.26 Å, CN 6 = 0.40 Å) and Eu 2+ (CN 6 = 1.17 Å, CN 8 = 1.25 Å) suggested that Eu 2+ should occupy the lattice position of Ca 2+ .…”

Recent Advances of Persistent Luminescence Nanoparticles in Bioapplications

“…Theoretically, we can synthesize persistent luminescence materials emitting any color by adjusting the chemical components. The most widely used and studied matrixes include silicates [9], gallium oxides [10], gallogermanates [11], aluminates [12] and so on [13][14][15][16]. Among them, CaAl 2 O 4 :Eu 2+ , Nd 3+ and SrAl 2 O 4 :Eu 2+ , Dy 3+ with overwhelming strong and long-lasting PL have been commercialized and widely used in various fields [2,17] [18][19][20].…”