Effect of annealing on the optical and magnetic properties of Mn3O4 nanoparticles embedded into Eu3+ doped borotellurite glasses.

Tuning the enhanced optical and magnetic properties of rare earth doped glasses by embedding nanoparticles is a never-ending quest. Influences of heat treatment (annealing) in modifying the spectral features of melt-quench synthesized manganese oxide nanoparticles (Mn 3 O 4 NPs) embedded Eu3+-doped borotellurite glasses are reported. The growth of NPs is tuned by varying the annealing time. TEM micrograph reveals the nucleation of heat treated Mn 3 O 4 NPs and SAED manifest their growth along the (1 1 2) crystallographic planes having average size in the range of 5.2 to 21.4 nm. The SPR bands are evidenced in the range 350 to 700 nm that validates the growth of Mn 3 O 4 NPs in the glass matrix. The luminescence spectra reveal four major emission peaks at 591, 614, 651 and 700 nm originating from 7F 1 , 7F 2 7F 3 , and 7F 4 transitions levels, respectively. Intensity enhancement displayed by heat treated glass samples is attributed to the local field effect of Mn 3 O 4 NPs while a quenching is due to the energy transfer from Eu3+ to Mn 3 O 4 NPs. The intensity parameters related to the radiative transitions within 4f configuration of Eu3+ ions are determined and analyzed using Judd-Ofelt theory. The magnetization versus field (M-H) at 12 h of Mn 3 O 4 NPs shows the highest saturation magnetization. The ESR spectrum exhibits resonance signals with effective isotropic g values at 1.9, 3.0 and 4.3 where g at 1.9 are attributed to Mn2+ centers in an octahedral asymmetry and g at 3.0 and 4.3 are attributed to the rhombic symmetry of the Mn2+ ions. Present glass compositions are established to be promising for the development of photonic devices. • Annealing time dependent optical and magnetic properties of melt quenching synthesized Eu3+ doped BT glasses containing Mn 3 O 4 NPs are reported. • The TEM result without and with annealed reveals the size of NPs while its planar spacing are determined by HRTEM. • The spectroscopic properties of the proposed glasses are determined. • J-O intensity parameters and radiative lifetimes, stimulated emission cross-section and quantum efficiencies are evaluated. • The magnetization measurement of glass sample is carried out using VSM and ESR. [ABSTRACT FROM AUTHOR]