ORALS

SESSION: SolidStateChemistryTuePM1-R6	Alario-Franco international Symposium (2nd Intl Symp on Solid State Chemistry for Applications & Sustainable Development)
Tue. 29 Nov. 2022 / Room: Andaman 1
Session Chairs: Hiroshi Kageyama; Session Monitor: TBA

14:00: [SolidStateChemistryTuePM105] OS
High sensitivity temperature probing of Mn4+ doped Li4Ti5O12 by lifetime-based luminescence thermometry
Zoran Ristic¹ ; Mina Medic¹ ; Vesna Djordjevic¹ ; Sanja Kuzman¹ ; Mikhail G. Brik² ; Miroslav Dramicanin¹ ; ¹University of Belgrade, Vinca Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro; ²Institute of Physics, University of Tartu,, Tartu 50411, Estonia;
Paper Id: 63 [Abstract]

<p>In this work we utilise luminescent properties of Mn⁴⁺ doped Li₄Ti₅O₁₂ - a very promising material for ultrafast-charge-discharge and long-cycle-life batteries [1]. Applying lifetime-based luminescence thermometry on Mn⁴⁺ doped materials the remote and non-contact temperature readings are possible with great relative sensitivity [2-4].<br />The Mn⁴⁺ doped Li₄Ti₅O₁₂ samples were prepared by the one step solid-state method using stoichiometric amounts of Li₂CO₃, TiO₂ and MnO₂ at 850 ^oC to obtain cubic spinel structure with space group Fd-3m as confirmed by X-ray diffraction analysis. In this host, Mn⁴⁺ is in a strong crystal field providing the strong absorption around 500 nm due to ⁴A_2g &rarr;⁴T_2g electric spin-allowed electron transition and with emission around 679 nm on account of ²E_g &rarr;⁴A_2g spin forbidden electron transition. Due to the coupling to phonon modes of the host material [5] the change of radiative decay rate (radiative lifetime) starts at very low temperatures (&raquo;75 K). In addition, the low value of energy of ⁴T_2g level (20000 cm&minus;1) leads to the strong emission and radiative lifetime quenching starting at low temperatures (&raquo;250 K) which favours the use of this material for the luminescence thermometry in a broad temperature range. <br />Temperature dependences of photo-luminescent emission spectra and emission decay are measured over the 10&ndash;350 K range exhibiting quite large value of relative sensitivity (2.6% K&minus;1@330 K) that facilitates temperature measurements with temperature resolution better than 0.15 K around room temperature.</p>

References:
<p>[1] Bote Zhao, Ran Ran, Meilin Liu, Zongping Shao ; A comprehensive review of Li4Ti5O12-based electrodes for lithium-ion batteries: The latest advancements and future perspectives ; Materials Science and Engineering: R: Reports,Volume 98,Pages 1-71, 2015\n[2] Sekulić, M., Ristic, Z., Milićević, B., Antić, Ž., Đorđević, V., &amp; Dramićanin, M. D. (2019). Li1.8Na0.2TiO3:Mn4+: The highly sensitive probe for the low-temperature lifetime-based luminescence thermometry. Optics Communications, 452, 342&ndash;346.\n[3] Li F., Cai J., Chi F.F., Chen Y., Duan C., Yin M.Investigation of luminescence from luag: Mn4+ for physiological temperature sensing, Opt. Mater., 66 (2017), pp. 447-452,\n[4]Glais E., Đorđević V., Papan J., Viana B., Dramićanin M.D.MgTiO3:Mn4+ a multi-reading temperature nanoprobe, RSC Adv., 8 (2018), pp. 18341-18346,\n[5] Senden T., van Dijk-Moes R.J.A., Meijerink A. Quenching of the red Mn4+ luminescence in Mn4+-doped fluoride LED phosphors, Light Sci. Appl., 7 (2018), p. 8</p>

SESSION: SolidStateChemistryTuePM2-R6	Alario-Franco international Symposium (2nd Intl Symp on Solid State Chemistry for Applications & Sustainable Development)
Tue. 29 Nov. 2022 / Room: Andaman 1
Session Chairs: Miguel Angel Alario Franco; Session Monitor: TBA

15:55: [SolidStateChemistryTuePM209] OS
Highly-sensitive Luminescence Thermometry of Sm2+ doped in Al2O3 Coatings
Aleksandar Ćirić¹ ; Zoran Ristic² ; Zeljka Antic³ ; Ivana Zeković² ; Stevan Stojadinović⁴ ; Mikhail G. Brik⁵ ; Miroslav Dramicanin² ; ¹Vinča Institute of Nuclear Sciences, Knjaževac, Serbia and Montenegro; ²University of Belgrade, Vinca Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro; ³Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia and Montenegro; ⁴University of Belgrade, Faculty of Physics, Belgrade, Serbia and Montenegro; ⁵Institute of Physics, University of Tartu,, Tartu 50411, Estonia;
Paper Id: 64 [Abstract]

<p><strong>Summary </strong> &gamma;-Al-2O3:Sm²⁺ coatings were synthesized by the plasma electrolytic oxidation (PEO). The emissions originate from 4f⁵5d¹&rarr;4f⁶ and 4f⁶&rarr;4f⁶ transitions of Sm²⁺. The emission spectra, recorded from 300 K to 673 K, reveled the rapid diminution of the ⁵D₀&rarr;⁷F_J transitions with increasing temperature. The 5d&rarr;4f broad-band emission increases in intensity up to 225 &deg;C. The high-luminescence intensities and opposite intensity vs temperature trends of these emissions are an indication of the high sensitivities and low temperature resolution. The luminescence intensity ratio (LIR) are well-fitted to the Boltzmann distribution and the energy-crossover model with relative sensitivities: 3.5 %K-1 @ 300 K and 1.5 %K-1 @ 540 K. <strong>Introduction</strong> Sm2+ has a wide excitation band [1]. The emission spectrum of Sm²⁺ features a broad-band due to 5d-4f transition and a series of sharp peaks due to 4f-4f transitions. The discovery of Al₂O₃:Sm²⁺ [1] provided an opportunity for the investigation of this material as temperature sensor. The indications of its high potential for the phosphor thermometry were the existence of both the 5d-4f and 4f-4f emissions, high emission intensities, wide choice of excitation wavelengths, and the sole importance of the substrate material itself. The significant overlap of 5d with ⁵D₀ level is an indication of the highly efficient f-f transitions [2]. The complete thermometric analysis was carried out. <strong>Methods</strong> 99.9% pure aluminium, 6061 and 7075 aluminium alloys were used as anode during the PEO. XRD was used for investigation of the coating crystallinity. High-stability 473 nm laser was used as an excitation source. The beams were transferred via a fiber-optic bundle. Emission spectra were recorded by the high-resolution spectrograph. The samples were placed on the liquid nitrogen cooled hot/cold stage. <strong>Results</strong> Emission spectra for LIR and LT were recorded from 100 K to 673 K. The ⁵D₀&rarr;⁷F_J emissions rapidly drop with increasing temperature, while the 4f-5d increases up to 225 &deg;C. LIR is estimated from the ratio of 5d-4f and 4f-4f transitions, giving the excellent relative sensitivity values. Luminescence lifetime of ⁵D₀&rarr;⁷F₀ is fitted to the energy crossover model [3], with maximum relative sensitivity 1.5 %K-1 @ 540 K. <strong>Conclusions</strong> A steady-state and time-resolved thermometry on a wide temperature range was carried out on the highly luminescent phosphor incorporated in the coatings of possibly the most important industrial material. LIR following Boltzmann distribution showed sensitivity among the highest ever recorded. The lifetime rapidly drops with increasing temperature.</p>

References:
<p>[1] S. Stojadinović, N. Tadić, R. Vasilić, Photoluminescence of Sm2+ / Sm3+ doped Al2O3 coatings formed by plasma electrolytic oxidation of aluminum, J. Lumin. 192 (2017) 110&ndash;116. https://doi.org/10.1016/j.jlumin.2017.06.043. [2] M. Tanaka, T. Kushida, Interference between Judd-Ofelt and Wybourne-Downer mechanisms in the 5D0-7FJ (J=2,4) transitions of Sm2+ in solids, Phys. Rev. B. 53 (1996) 588&ndash;593. https://doi.org/10.1103/PhysRevB.53.588. [3] M. Sekulić, Z. Ristić, B. Milićević, Ž. Antić, V. Đorđević, M.D. Dramićanin, Li1.8Na0.2TiO3:Mn4+: The highly sensitive probe for the low-temperature lifetime-based luminescence thermometry, Opt. Commun. 452 (2019) 342&ndash;346. https://doi.org/10.1016/j.optcom.2019.07.056.</p>