Emission analysis of RE3+ (Eu3+, Tb3+ & Ho3+) : B2O3–BaO­LiF/AIF3 glasses

We report here the luminescence spectra of certain rare earth ions (Eu3+, Tb3+ & Ho3+) doped B2O3-BaO-LiF/AiF3 based on the measurements of emission and decay curves of prominent emission transitions. For both the reference host glasses, FTIR, XRD, DTA-TG profiles have been recorded to understand their structural and thermal properties. Eu3+ doped glasses have shown five emission transitions of 5D0 . 7F01,2,3 & 4 located at 580nm, 593nm, 615nm, 655nm and 704nm respectively with an excitation at .exci = 392 nm (7F0 . 5L6). Also under an UV source, these europium glasses have displayed a bright red emission from their surfaces. Tb3+ glasses have exhibited four emission bands of 5D4 . 7F6,5,4,3 at 491nm, 547nm, 588nm and 625nm respectively with an excitation at .exci = 376 nm (7F6 . 5G6). Intense green emission from the glass surfaces has been noticed upon exposure to the UV source. Prominently bluish-green emission has been noticed from the surfaces of the holmium glasses under an UV source and same emission transition (5F4 . 5I8) at 519 nm with an excitation at .exci = 389 nm (5I8 – 5G4) has also been obtained from their measured emission spectra. For all the prominent emissions of the rare earth glasses, decay curves have been measured to compute their lifetimes.Emission analysis of RE3+ (Eu3+, Tb3+ & Ho3+) : B2O3–BaO­LiF/AIF3 glasses B H Rudramadevi and S Buddhudu* Department of Physics, Sri Venkateswara University, Tirupati-517 502, Andhra Pradesh, India E-mail : [email protected] of Physics, Sri Venkateswara University, Tirupati-517 502, Andhra Pradesh, Indi

Light-emission in Tb³⁺and Eu³⁺: PVP polymer films

377-381Analysis of photoluminescence spectra of PVP and Tb3+ or Eu3+: PVP polymer films has been done. Emission spectrum of the host matrix poly (vinyl pyrrolidone) (PVP) has shown an intense blue emission at 424 nm [π0→ n1π2]. By using a solution cast method, more clear and transparent PVP polymer films have been developed for analysis with the addition of Tb3+ and Eu3+ ions separately into PVP polymer matrix; green and red colour emitting polymer films have been developed. Also undoped PVP polymer film has been prepared as a reference film for which XRD, FTIR, Raman and TGA-DTA spectral profiles have been carried out. From the measured emission spectrum of the Tb3+: PVP polymer film, an intense green emission at 544 nm (5D4→7F5) has been observed with an excitation at 311 nm. Under an UV source a bright green emission has been noticed from the surface of the Tb3+: PVP polymer film, and a bright red emission has been noticed from the surface of the Eu3+: PVP polymer film. The emission spectrum of Eu3+: PVP polymer film has also revealed an intense red emission at 612 nm (5D0→7F2)

<span style="mso-bidi-language:HI">Spectral analysis of Cu²^{<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">+</span>}<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">: <span style="mso-bidi-language:HI">B₂O₃-(TeO₂/CdO/ZnO)-Li₂O-AlF₃ glasses </span></span></span>

887-895The development and optical spectral analysis of Cu2<span style="mso-bidi-font-family:Arial;mso-bidi-language: HI">+<span style="mso-bidi-font-family:Arial;mso-bidi-language: HI"> (0.5 mol %) doped three new glasses have been reported in the following composition: 10TeO2-69.5 B2O3-10 Li2O-10 AIF3; 10ZnO-69.5 B2O3-10 Li2O-10 AIF3; 10ZnO-69.5 B2O310 Li2O-10 AIF3. Due to the homogeneous distribution of Cu2+ ions, both CdO and ZnO containing glasses are found to be in bright blue colour, but a greenish blue colour has been noticed from the TeO2 containing glass, the reason for this has been explained. Without the Cu2<span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">+<span style="mso-bidi-font-family: Arial;mso-bidi-language:HI"> ions, the reference glasses have also been prepared and found them in good transparency with excellent resistance towards the moisture without any degradation on their surfaces. Based on the XRD profiles, amorphous nature of these glasses has been confirmed. Due to the presence of TeO2, the UV transmission for the glass is found to be extended up to 300 nm compared with the other two glasses. Under an UV source (254 nm), a blue emission has been noticed from the surfaces of the glasses. From the measured absorption spectra of these copper glasses, a abroad absorption band (2B1g → 2B2g) at 800 nm and a weak absorption band (2B1g → 2B2g) at 387 nm have been measured to examine the effects of the CdO, ZnO and TeO2 contents in the glasses studied. FTIR spectra of these glasses have also been analyzed to investigate the glass structures. Emission spectra of (0.5 mol %) Cu2+: B2O3-(TeO2/CdO/ZnO)-Li2O-AlF3 have revealed two emissions at 415 and 438 nm with an excitation at 371 nm. </span

<span style="font-size:10.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-US">Synthesis and characterization of Mn²⁺: LiNbO₃ nano-particles by co-precipitation method</span>

245-250By employing a co-precipitation method, nano particles of LiNbO3 doped with Mn2+ ions have been synthesized from an appropriate stoichiometry of Li0.5Mn0.25NbO3 (which is labeled as LMN). These nano materials have been sintered at different temperatures of 700°, 8000, 900<span style="font-family:Symbol; mso-ascii-font-family:" times="" new="" roman";mso-hansi-font-family:"times="" roman";="" mso-char-type:symbol;mso-symbol-font-family:symbol"="" lang="EN-GB">° and 1000°C, respectively in order to evaluate an optimized sintering temperature, based on the measurements of XRD profiles. Morphology of the LMN samples has been examined by HRSEM images. Elemental analysis of the sample has been confirmed from EDAX analysis. Besides that, Raman and FTIR spectral profiles have been carried out. Thermal (TGA/DTA and also DSC), magnetic, dielectric ' & '', ac-conductivity (ac) properties have also been studied for the LMN sample. To understand the structural details of the samples, we have synthesized LiNbO3 nano particles in addition to Li0.5Mn0.25NbO3 and made a comparison. These preliminary studies have been undertaken to identify their suitability for various applications. </span

<span style="mso-bidi-language:HI">Emission spectra of Eu³^{<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">+</span>}<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI"> <span style="mso-bidi-language:HI">and Tb³^{<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">+</span>}<span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">: <span style="mso-bidi-language:HI">Borophosphate oxyfluoride glasses </span></span></span></span></span>

496-500    The development and luminescence properties of (0.2 mol <span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">%) of Eu3+ and Tb3+ ions doped borophosphate oxyfluoride (BPOF) optical glasses have been reported in the following general compositions:     69.8 B2O3.10 P2O5-10 <span style="mso-bidi-font-family:Arial; mso-bidi-language:HI">(ZnO/CdO/TeO2)-10 (A1F3/LiF)     Measured emission spectra of Eu3+: BPOF optical glasses have revealed five emissions (5D0→7F0.1.2.3&4) at 580, 591, 613, 654 and 701 nm, respectively with λexci = 392 nm (7F0→5L6). In case of Tb3+: BPOF optical glasses, four emissions (5D4→7F6,5,4&3) that are located at 489, 545, 584 and 622 nm have been measured with λexci = 374 nm. For the red (Eu3+) and green (Tb3+) emission bands, decay curves have been recorded to compute their lifetimes. By using relevant energy level diagrams, emission processes in the glasses have been explained. </span