High pressure effect on structural and spectroscopic properties of Sm³⁺-doped alkali silicate glasses

ABSTRACT

Structural and spectroscopic properties of Sm³⁺-doped alkali silicate glasses were investigated after densification at 7.7 GPa in a large volume high pressure apparatus. The glass composition was 33M₂O + 66SiO₂ + 1Sm₂O₃, where M = Li, Na or K. Raman and infrared spectroscopy revealed small changes in the vibrational modes dependent on the alkali ion. Irreversible changes were observed in the optical absorption spectra of Sm³⁺ ions. The Judd–Ofelt parameters were calculated to evaluate the effect of pressure on the local field. For lithium silicate, Ω₂ parameter increased, suggesting the densification increased the local asymmetry of the Sm³⁺ environment. For sodium silicate, this parameter decreased considerably, suggesting the opposite effect on the local field, while for potassium silicate, it remained practically unchanged. The changes induced by high pressure are probably due to the irreversible changes in the distances and bond angles between the rare earth ion and the ligands.

KEYWORDS:

• High pressure
• alkali silicates
• luminescence
• samarium

Acknowledgements

For financial support of Brazilian agencies CAPES, CNPq and FAPERGS and to Paulo Franzen from the Microelectronic Group of the Institute of Physics of UFRGS for the spectroscopic characterization, the authors extend their thanks.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Naira Maria Balzaretti http://orcid.org/0000-0003-2797-8618

Additional information

Funding

This work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico [grant number 442122/2014-4]; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul [grant number 2354-2551/14-3].