title: Mixed alkali effect in Mn2+ doped 20ZnO+xLi2O+(30-x)K2O+50B2O3(5≤x≤25) glasses.
abstract: Divalent Mn2+ ions containing 20ZnO+xLi2O+(30-x)K2O+50B2O3(5≤x≤25) mol% glasses are prepared by using melt quench technique and are characterized by several spectroscopic techniques. Various physical parameters are evaluated from the measured values of density and refractive index for the observation of mixed alkali effect. Structural changes of Mn2+ doped ZLKB glasses are investigated by Powder XRD, UV-VIS absorption, Electron Paramagnetic Resonance and FT-IR spectroscopic studies. The XRD pattern indicates the amorphous nature of prepared glasses. FT-IR measurements of all glasses revealed that the network structure of glass system are mainly based on BO3 and BO4 units placed in different structural groups in which the BO3 units being dominant. The EPR spectra of Mn2+ ions doped glasses exhibited a characteristic hyperfine sextet around g=2.0. The spectroscopic analyses of the obtained results confirmed near octahedral site symmetry for the Mn2+ impurity ions. Crystal field and Racah parameters are evaluated from optical absorption spectra. The optical band gap and Urbach energies are determined which exhibited the mixed alkali effect.
authors.affiliation: Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, India.
authors.forename: G Krishna
authors.initials: GK
authors.lastname: Kumari
authors.forename: Ch Rama
authors.initials: ChR
authors.lastname: Krishna
authors.forename: Sk Muntaz
authors.initials: SM
authors.lastname: Begum
authors.forename: V Pushpa
authors.initials: VP
authors.lastname: Manjari
authors.forename: P N
authors.initials: PN
authors.lastname: Murthy
authors.forename: R V S S N
authors.initials: RV
authors.lastname: Ravikumar
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D005898:Glass / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D033362:Powder Diffraction; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D000468:Alkalies; D001896:Boron Compounds; D018020:Lithium Compounds; D010087:Oxides; D017680:Potassium Compounds; C042168:boron oxide; C068440:potassium oxide; D008274:Magnesium; D015034:Zinc Oxide