ESR Study of Manganese-Doped α-Zinc Silicate Crystals

Abstract

Single crystals of dilute manganese-doped α-Zn2SiO4 have been grown hydrothermally and from the melt. ESR spectra have been examined at 9.5 and 35 Gc/sec. Results are interpreted in terms of Mn2+ at two environmentally different sites, having D parameters 729±8 and 413±4 G and E parameters 170±5 and 135±5 G, respectively. The relative population of the two sites appears to be independent of total manganese concentration or method of crystal growth. It is believed that the two sites correspond to substitution of Mn2+ for Zn2+ at two crystallographically nonequivalent zinc positions in the willemite structure.

Photoluminescece and Thermoluminescence Behavior of Zn2SiO4: Mn2+, Eu2+ Phosphor

“…The sample exhibit almost identical XRPD patterns corresponding to the Will emit structure of the usual rhombohedral phase of Zn2SiO4 (Lina et al, 2000). The Mn 2+ and Eu 2+ ions substitute for the Zn 2+ in the Zn2SiO4 host, which has tetrahedral sites (Perkins et al, 1967;Stevels et al, 1974, Yang et al, 2003. No XRPD peaks from impurities are observed in the samples, thus, it is reasonable to assume that Mn 2+ and Eu 2+ ions substitute for Zn 2+ sites in the Zn2SiO4 host lattice.…”

A Novel Synthetic Route for Green-emitting Zn2-xMnxSiO4Phosphor using Colloidal Silica

“…The emission band is assigned to transitions between the spin-orbit components of the 4 T 1 excited state and the 6 A1 ground state. 2,15,17,18 Figure 5 shows the PL spectra of Zn 1.92 Mn 0.08 SiO 4 prepared at different temperature between 800 o C and 1200 o C. All emission spectra were obtained under 254 nm excitation. The PL spectra show that the PL intensity of the Zn 1.92 Mn 0.08 SiO 4 phosphor increases as the synthetic temperature increases.…”

“…2,15 Mn 2+ has d 5 configuration with high spin (S = 5/2). The emission band is assigned to transitions between the spin-orbit components of the 4 T 1 excited state and the 6 A1 ground state.…”

“…4,5 In the synthesis of Zn 2-x Mn x SiO 4 , the solid state reaction is difficult to control the distribution of the doped metal ions and the morphology of the particles, and avoid the aggregation of the willemite (rhombohedral structure R3) particles. 6 In order to overcome these problems, many methods for preparation of the Zn 2-x Mn x SiO 4 have been proposed, such as sol-gel method, 7 polymer precursor method, 8 spray pyrolysis method, 9 and hydrothermal method.…”

“…[10][11][12][13] Especially, sol-gel technique offers several processing advantages over many material production methods, mainly due to purity, homogeneity, lower calcining temperature. 14,15 In the syntheses of Zn2-xMnxSiO4 using sol-gel method, tetraethyl orthosilicate (TEOS) is generally used as a Si-source. However, the reagent has some problems such as organic pollutants and complicated process including hydrolysis step.…”