Effect of Yb3+ codopant on the upconversion and thermoluminescent emission of Sr2CeO4:Er3+, Yb3+ phosphors

Blue/NIR-emitting Phosphor Based on Sr2CeO4: Tm3+, Yb3+ Obtained by Combustion Synthesis

“…The most intense diffraction peaks correspond to (130), ( 111) and (221) orientations at 2θ = 29.9º, 2θ = 30.4º and 2θ = 42.8º respectively which are labelled on the SCO 7.0 XRD pattern. The lattice parameters and the volume listed in Table 1 have reduced from 222.5 ų (SCO 0.5 sample) which is close to the reported in the literature of 227.62 ų [13] and slightly decreases to 221.03 ų (SCO 7.0 sample) which reveals that the lattice contraction of the crystalline structure network could be attributed to the Yb 3+ and Tm 3+ are lower in ionic radii than Sr 2+ and Ce 4+ respectively as reported by Viesca-Villanueva et al [14].…”

“…X-ray diffraction patterns of Sr2CeO4 and various codopants concentrations: Yb = 0.5, 1.0, 1.5, 3.0, 5.0, 7.0 mol % and Tm = 0.5 mol % (fixed). SCO sample is without co-dopantsThe a, b and c lattice parameters were calculated by using the diffraction peaks located at 2θ = 29.15º, 34.62º and 42.8º which corresponds to (200), (040) and (221) planes respectively to confirm the results.The lattice parameters and the volume listed in Table1have reduced from 222.5 ų (SCO 0.5 sample) which is close to the reported in the literature of 227.62 ų[13] and slightly decreases to 221.03 ų (SCO 7.0 sample) which reveals that the lattice contraction of the crystalline structure network could be attributed to the Yb 3+ and Tm 3+ are lower in ionic radii than Sr 2+ and Ce 4+ respectively as reported by Viesca-Villanueva et al[14].The crystallite size was calculated using the Scherrer equation[15] with the formula:…”

“…This fact could create an imbalance of charges that causes a random growth of the microparticles with big sizes and irregular shapes because of the high content of Yb 3+ [16]. This decrement in grain sizes of SCO 5.0, has been reported in the literature for other phosphors that enhance the photoluminescence intensity [14]. The texture coefficient Tc(hkl) [17] of the hkl planes for SCO, SCO 1.0, SCO 3.0, SCO 5.0 and SCO 7.0 samples were obtained from the measured intensity I(hkl) and the relative intensity Io(hkl) of the corresponding plane given in JCPDS 50-0015 standard card, also n is the number of diffraction peaks.…”

Materials AIILnInO4 with Ruddlesden-Popper Structure for Electrochemical Applications: Relationship between Ion (Oxygen-Ion, Proton) Conductivity, Water Uptake, and Structural Changes

“…For the last 30 years, different compositions with K 2 NiF 4 or related structures were described as superconductors [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ], giant and colossal magnetoresistors [ 27 , 28 , 29 , 30 ], microwave dielectrics [ 31 , 32 , 33 , 34 , 35 ], phosphors [ 36 , 37 , 38 , 39 ], mixed ionic and electronic conductors (MIEC) [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], dielectrics [ 51 , 52 , 53 , 54 , 55 ], magnetic materials [ 56 , 57 , 58 ], thermoelectrics [ 59 , 60 , 61 , 62 ], photocatalysts for hydrogen production [ 63 , 64 , 65 ], oxygen-ionic conductors [ 66 , 67 ,…”

Ce doping induced trapping states and local electronic structure modifications in SrZnO2 nanophosphors

“…The singly occupied 4f 1 state acts as an electron donor and hole trapping centre, while the empty 4f 0 state can act as electron trapping centre. 7,8 However, it is interesting to note that the host SrZnO 2 possesses two cation sites (Zn and Sr) of varying ionic radii and coordination environments. 9 The effect of increasing the Ce doping concentration, accompanied by variable site occupancy, charge balancing and the relative concentration of 4f 0 -4f 1 trapping states is expected to bring interesting modifications to the system.…”