Engineering defect clusters in distorted NaMgF₃ perovskite and their important roles in tuning the emission characteristics of Eu³⁺ dopant ion

Abstract

Defect engineering in distorted NaMgF3 can be achieved by doping different amounts of dopant (Eu3+) and co-dopant (Li+) ions, which has a significant impact on the emission spectrum and photoluminescence decay profile of the Eu3+ ion.

Divalent and trivalent neodymium photoluminescence in NaMgF3:Nd

“…1, where the major excitations and emissions occurred due to the presence of Nd 3+ ions. Based on previous studies of NaMgF 3 :Ln materials, it is expected that the Nd 3+ ions substitute the Na + sites of the NaMgF 3 host [34][35][36]. This interpretation is reinforced by the relevant ionic radii, where in 8-fold coordination the ionic radii of Nd 3+ and Na + are 1.11 Å and 1.18 Å, respectively [37].…”

Defect-assisted dynamic multicolor modulation in KLu3F10:Tb crystals for anti-counterfeiting

“…2b). By fitting the decay curve with a tri-exponential function, 30–32 the lifetime of 442 nm was calculated to be 7.93 ns, while that of Tb 3+ : 5 D 4 → 7 F 5 (545 nm) was calculated to be 6.06 ms (Fig. 2c and d).…”

Tailoring defect structure and dopant composition and the generation of various color characteristics in Eu3+ and Tb3+ doped MgF2 phosphors

“…We carried out PALS measurements at room temperature for various Eu 3+ and Tb 3+ doped MgF 2 samples following the experimental procedure, data analysis and theoretical calculations using the MIKA-DOPPLER package, same as described elsewhere. 32,33 The PALS histogram profile for various compounds is shown in Fig. 5.…”

“…For understanding the experimentally observed positron lifetime components in both the un-doped and doped samples a theoretical positron lifetime in the matrix was calculated using the first-principal methods implemented in the MIKA/DOPPLER package. 39–42 The method of calculation is also briefly described in ref. 32 a Electron and positron densities in the matrix are calculated using two-component generalization of the density functional theory.…”

“…In many cases, if such defect centres exist close to the dopant ions then they may have a significant impact on the emission properties of the dopant ion and such studies are also very essential while developing efficient phosphor materials. 32 For example, we have demonstrated earlier that by tailoring the defect centres and their cluster forms surrounding the Eu 3+ ion in MgF 2 , it is possible to tune all 5 D 0 – 7 F 1 , 5 D 0 – 7 F 2 and 5 D 0 – 7 F 4 transitions of the Eu 3+ ion, which has a direct impact on the colour characteristics of the phosphor materials. 33 This is due to the fact that such defect clusters change the symmetry surrounding the dopant ion and transitions, such as the electrical dipole (ED), are highly sensitive to any change in the local structure or site symmetry.…”