Crystal Interface Control at Low Thermal Gradient and Investigation of the Effect of Cr on the Crystal Structure and Optical Properties of Bismuth Silicate. Issue 12 (8th October 2021)

• Record Type: Journal Article
• Authors: Bhaumik, Indranil; Ananthu Vijayan, V. L.; Bhatt, Rajeev; Soharab, Mohammad; Ganesamoorthy, Sarveswaran; Karnal, Ashwani Kumar
• Is Part Of: Physica status solidi. Volume 258:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-08
• Subjects: bandgap energies -- refractive indices -- single crystals; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.202100315
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : Single crystals of bismuth silicate (Bi12 SiO20 ) doped with chromium (0.05, 0.25, 0.5, and 1.0 at%) have been grown along ⟨110⟩ by Czochralski technique. The effect of growth parameters like low axial thermal gradient and crystal rotation rate on the crystal−melt interface is investigated by varying these parameters. Further, the effect of Cr incorporation on the lattice parameter, optical bandgap, emission characteristics, and refractive index is studied. It is observed that as the concentration of Cr increases, the lattice parameter increases, because the size of Cr ion is higher than that of Si ion which it replaces. The bandgap is found to decrease with the increase in the concentration of Cr in the lattice of Bi12 SiO20 . The estimated bandgap energy of all the samples lies between 2.16 and 3.12 eV. The estimated Urbach energy is ≈115 meV for undoped BSO and it is slightly higher (≈200 meV) for Cr‐doped crystals. Further, 0.05 and 0.25 at% Cr‐doped samples exhibit emission peak at around 470 nm on excitation at 420 nm. The refractive index is found to decrease with the increase in Cr concentration in the lattice. Abstract : The effect of growth parameters like low axial thermal gradient and crystal rotation rate on the crystal−melt interface of Bi12 SiO20 single crystal during growth by the Czochralski method is investigated. Further, the effect of Cr incorporation on the lattice parameter, optical bandgap, emission characteristics, and refractive index of Bi12 SiO20 is studied.