Synthesis and Characterization of Li2MgGeO4:Ho3+

Abstract

In this work, the synthesis and characterization of Li2MgGeO4:Ho3+ ceramics were reported. The X-ray diffraction measurements revealed that the studied ceramics belong to the monoclinic Li2MgGeO4. Luminescence properties were analyzed in the visible spectral range. Green and red emission bands correspondent to the 5F4,5S2→5I8 and 5F5→5I8 transitions of Ho3+ were observed, and their intensities were significantly dependent on activator concentration. Luminescence spectra were also measured under direct excitation of holmium ions or ceramic matrix. Holmium ions were inserted in crystal lattice Li2MgGeO4, giving broad blue emission and characteristic 4f-4f luminescent transitions of rare earths under the selective excitation of the ceramic matrix. The presence of the energy transfer process between the host lattice and Ho3+ ions was suggested.

Comparative Upconversion Emission Study of XWO4:Ho3+-Yb3+(X= Ba, Ca, Sr) Phosphors

“…Three main UC emission bands were detected around 544, 653, and 757 nm in Figure 3. These emission bands well assigned by the 5 F4/ 5 S2→ 5 I8, 5 F5→ 5 I8 and 5 S2→ 5 I7 transitions of the Ho 3+ ion (Pandey et al, 2016;Pandey et al, 2017;Pandey et al, 2018;Bednarska-Adam, 2022). The codoping of the Yb 3+ ion empowered the performance of the activator Ho 3+ ion.…”

“…A two photon pumped energy transition scheme with possible ground state absorption (GSA), excited state absorption (ESA), and energy transfer (ET) processes of the Ho 3+ and Yb 3+ ions are presented in Figure 4. The energy level diagram of the Ho 3+ and Yb 3+ ions show the ground state ( 5 I8) Ho 3+ ions pumped to the excited states 5 I5,6 and 5 F2,3,4 via a consecutive absorption of two photons through GSA and ESA processes as indicated (Pandey et al 2016;Pandey et al, 2017;Bednarska-Adam 2022). The populations in these states were amplified by the efficient ET from the Yb 3+ ions.…”

Li4GeO4-Li2CaGeО4 phase equilibria and Li2+xCa1-xGeO4 solid solutions

“…The intermediate compounds from these systems Li 2 ZnGeO 4 , Li 2 MgGeO 4 and Li 2 CaGeO 4 have been tested also as dielectric ceramics [ 5 , 6 ] and phosphors [ [7] , [8] , [9] , [10] , [11] ]. Another promising application of these intermediates is for solid-state laser media doped with Cr 4+ possessing a wide spectrum of radiation in the near infrared region (1.1–1.6 μm) [ 12 , 13 ].…”