Tm,Ho:Ca(Gd,Lu)AlO4 crystals: Crystal growth, structure refinement and Judd-Ofelt analysis

• Published in: Journal of luminescence 2022-06, Vol.246, p.118828, Article 118828
• Main Authors: Pan, Zhongben, Loiko, Pavel, Slimi, Sami, Yuan, Hualei, Wang, Yicheng, Zhao, Yongguang, Camy, Patrice, Dunina, Elena, Kornienko, Alexey, Fomicheva, Liudmila, Wang, Li, Chen, Weidong, Griebner, Uwe, Petrov, Valentin, Solé, Rosa Maria, Díaz, Francesc, Aguiló, Magdalena, Mateos, Xavier
• Format: Article
• Language: English
• Subjects: Aluminate crystals; Czochralski growth; Judd-Ofelt theory; Optical absorption; Optics; Physics; Raman spectra; Structure refinement
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2022.118828

“Mixed” calcium rare-earth aluminate laser host crystals Ca(Gd,Lu)AlO4 (CALGLO) with up to 10.8 at.% Lu codoped with Tm3+ and Ho3+ ions are grown by the Czochralski method along the [001] direction. The segregation of rare-earth ions is studied. The crystal structure is refined by the Rietveld method. Tm,Ho:Ca(Gd,Lu)AlO4 crystallizes in the tetragonal system (sp. gr. I4/mmm) exhibiting a K2NiF4 type structure. The lattice constants are a = 3.6585(6) Å and c = 11.9660(9) Å for a crystal with a composition of CaGd0.8947Lu0.0551Tm0.0448Ho0.0054AlO4. The stability of Ca(Gd,Lu)AlO4 solid-solutions is discussed. The polarized Raman spectra are measured, revealing a most intense mode at 311 cm−1 and a maximum phonon frequency of ∼650 cm−1. The polarized absorption spectra are measured. The transition intensities for the Ho3+ ion are analyzed using the modified Judd-Ofelt theory accounting for configuration interaction. •Tm3+,Ho3+-codoped “mixed” disordered Ca(Ga,Lu)AlO4 aluminate crystal.•Rietveld refinement of the crystal structure and discussion of the crystal disorder.•The stability of CaGd1-xLuxAlO4 solid-solutions is discussed.•Polarized Raman spectra are measured, revealing the most intense mode at 311 cm−1.•Transition intensities for Ho3+ ions are analyzed using the modified Judd-Ofelt theory.