Mechanoluminescence Study of Europium Doped CaZrO3 Phosphor
Neha Tiwari, Vikas Dubey & R. K. Kuraria
Journal of Fluorescence ISSN 1053-0509 J Fluoresc DOI 10.1007/s10895-016-1817-0
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Author's personal copy J Fluoresc DOI 10.1007/s10895-016-1817-0
ORIGINAL ARTICLE
Mechanoluminescence Study of Europium Doped CaZrO3 Phosphor Neha Tiwari 1 & Vikas Dubey 2 & R. K. Kuraria 1
Received: 29 December 2015 / Accepted: 26 April 2016 # Springer Science+Business Media New York 2016
Abstract Behaviour displayed by mechanoluminescence (ML) in CaZrO3:Eu3+ doped phosphors with variable concentration of europium ions are described. When the ML is excited impulsively by the impact of a load on the phosphors the ML intensity increases with time, attains a maximum value and then it decreases. In the ML intensity versus time curve, the peak increases and shifts towards shorter time values with increasing impact velocities. Sample was synthesized by combustion synthesis method with variable concentration of Eu3+ ions (0.1, 0.2, 0.5, 1, 1.5 mol%) and characterized by X-ray diffraction technique. The total ML intensity IT is defined as the area below the ML intensity versus time curve. Initially IT increases with impact velocity V0 of the load and then it attains a saturation value for higher values of impact velocities which follow the relation IT = IT0 exp.(−Vc/V0) where IT0 and Vc are constants. Total ML intensity increases linearly with the mass of the phosphors for higher impact velocities. The ML intensity Im, corresponding to the peak of ML intensity versus time curve increases linearly with the impact velocities. The time tm, is found to be linearly related to 1000/V0. The mechanoluminescence induced by impulsive excitation in europium doped CaZrO3 phosphors plays a significance role in the understanding of biological sensors and display device application.
Keywords ML . Biological sensors . Total ML intensity IT
* Neha Tiwari
[email protected]
1
Department of Physics, Government Model Science College, Jabalpur, M. P., India
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Department of Physics, Bhilai Institute of Technology, Kendri, Raipur 493661, India
Introduction Mechanoluminescence (ML) is the phenomenon of light emission from a solid as a response to the mechanical stimulus given to it. The light emission induced by elastic deformation, plastic deformation and fracture of solids is known as elastico ML, plastico ML and fracto ML, respectively. The ML induced by rubbing of solids or separation of two solids in contact is known as tribo ML or triboluminescence [1]. In the recent past, several materials have been investigated, which emit intense ML during their elastic deformation, plastic deformation, and fracture. These materials have been reported to be useful in stress sensor [2, 3], fracture sensor [4, 5], damage sensor [6], and in the fusesystem for army warhead [7]. The ML has also been reported to be useful in the online monitoring of grinding in milling machines [8], and in radiation dosimetry [1]. ML and PL are examined by comparing their energy relationship. The spectral distribution is found to be similar, in ML, PL and EL. However the mechano – excitation is not necessarily a Franck – condon transition as in photo excitation. In ML and PL, the excited state lifetime is long enough to relax to an equilibrium state. The ML and PL should both represent a Franck – condon transition to the ground state [9–16]. The present paper describes ML behaviour of europium doped CaZrO3 phosphor and its dependency of concentration and impact velocity.
Experimental The starting reagents are high purity Ca(NO 3 ) 2.4H 2O, ZrO(NO3)2, Eu(NO3)3·6H2O and urea. Mixtures was mixed in stoichiometric amount of metal nitrates were dissolved in minimum quantity of deionized water in 200 mL capacity pyrex beaker. Then urea was added in this solution with molar
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ratio of urea to nitrates based on total oxidizing and reducing valencies of oxidizer and fuel (urea) according to concept used in propellant chemistry [18]. Finally the beaker containing solution was placed into a preheated furnace maintained at 600 °C. The material underwent rapid dehydration and foaming followed by decomposition, generating combustible gases. These volatile combustible gases ignite and burn with a flame yielding voluminous solid. Urea was oxidized by nitrate ions and served as a fuel for propellant reaction. The powders obtained were then further calcined from 600 °C for 3 h to increase the luminescence efficiency [19, 20]. The XRD measurements were carried out using Bruker D8 Advance X-ray diffractometer. The X-rays were produced using a sealed tube and the wavelength of X-ray was 0.154 nm (Cu Kα). The X-rays were detected using a fast counting detector based on Silicon strip technology (Bruker Lynx Eye detector). Observation of particle morphology was investigated by FEGSEM (field emission gun scanning electron microscope) (JEOL JSM-6360). ML pattern and ML spectra recorded by homemade apparatus which was reported by elsewhere [14–34].
Results The XRD pattern of the sample is shown in Fig. 1. The XRD pattern recorded for fixed concentration of Eu3+ (1.5 %). The width of the peak increases as the size of the crystallite decreases. The size of the crystals has been computed from the full width half maximum (FWHM) of the intense peak using Scherer formula [30–34]. Crystallite size of sample in the range 58 nm is found. Formula used for calculation is D¼
0:9λ β cos θ
Fig. 2 SEM image of Eu3+ doped CaZrO3 phosphor
Here D is particle size. β is FWHM (full width half maximum). λ is the wavelength of X ray source. θ is angle of diffraction. From XRD technique it is found that the sample shows most of the pure phase there is no any effect of impurity ion on phasing of the sample. Peaks matches with JCPDS card No. 20–0254 and shows cubic structure of prepared sample.
Sem Results The SEM image recorded for optimized concentration of Eu3+ (1.5 mol%) in CaZrO3 host lattice. The surface morphology shows the formation of flake type structure of prepared phosphor and it has some agglomerates when sample was prepared by solution combustion technique (Fig. 2).
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Ml Results In present study ML is excited impulsively, and ML emission is mostly due to deformation of the powder samples. In such cases only one peak is observed in the transient ML intensity curve. The characteristics of ML of CaZrO3:Eu3+ phosphor induced by the impact of a moving piston of weight 500 g onto the phosphors were measured (Fig. 3). Single peak is observed in ML intensity versus time curve. The presence of a single peak indicates some charge transfer process involved in ML emission. The luminescence intensity depends upon impact velocity. The experiment was carried out for different impact velocities i.e. same weight dropped with different heights. In Fig. 3 ML intensity increases with increasing concentration of europium ion and found maximum at 1.5 mol% of Eu3+ then intensity decreases due to concentration quenching (Fig. 4).
Fig. 6 Peak ML intensity vs Impact velocity
Figure 5 shows the time dependence of the ML intensity of CaZrO3:Eu3+ phosphor. It is seen that ML intensity initially increases with time attain a peak value and then decrease with time. The ML intensity Im corresponding to the peak in the ML intensity versus time curve, increases with increasing impact velocity of piston (Fig. 6). Figure 7 shows the dependence of the time tm corresponding to the peak in ML intensity versus time curve on the impact velocity for CaZrO3:Eu3+. It is seen that tm decreases with increasing impact velocity. Figure 8 shows dependence of total ML intensity IT (i.e. the area below the ML intensity versus time curve) on impact velocity for CaZrO3:Eu3+ phosphor. It is seen from the figure that IT initially increases with increasing impact velocity and then it tends to attain a saturation value for higher value of the impact velocity. Figure 9 shows mechanoluminescence spectra for CaZrO3:Eu3+. In Mechanoluminescence spectra a sharp single
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Fig. 7 Dependence of tm on impact velocity of CaZrO3:Eu3+ phosphor
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Fig. 8 Impact velocity dependence of total ML intensity I T of CaZrO3:Eu3+ (1.5 mol%)
peak is found at about 612 nm which was compared with the Photoluminescence spectra of the same sample (Fig. 10) and both the spectra found to be very similar in peak intensity as well as shape. It is found that an intense peak found at 612 nm in both spectra. Figure 11 shows the dependence of total ML intensity IT on the mass of phosphor. Total ML intensity linearly increases with increasing the mass of phosphor. Figure 12 shows the dependence of peak intensity Im of ML intensity versus time curve of CaZrO3:Eu3+ phosphor on the impact velocity Vo. It is seen that for higher values of the impact velocity, peak intensity Im increases linearly with the impact velocity. It seen from Fig. 13 that the total intensity IT of ML, defined as the area below the ML intensity versus time curve, of impurity doped phosphors, initially increases with the impact
ML spectra CaZrO3:Eu
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Fig. 10 photoluminescence Spectrum of CaZrO 3:Eu3+ (1.5mol%) phosphor
velocity Vo and then it attains a saturated value for higher values of the impact velocity for lower values the impact velocity. Figure 13 shows that the plot of log (IT) versus 1/V0 is a straight line with a negative slop, which suggests the relation. IT ¼ IT 0 expð−Vc = V0 Þ
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Where IT0 and VC are constants. IoT is initial total intensity and VC is the velocity corresponding to IT. Figure 14 shows the dependence of the time ‘tm’ corresponding to peak in the ML intensity versus time curve on increasing values of the impact velocity. Figure 15 shows that for higher values of the impact velocity, the plot of tm versus 1/V0 is a straight line with positive slope. Figure 16 shows the t-tm versus ML intensity plot which indicate negative slope for different impact velocity.
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Fig. 9 Mechanoluminescence Spectrum of CaZrO3:Eu3+ (1.5mol%) phosphor
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Fig. 11 Dependence of total impact velocity on the mass of phosphor (1.5 mol%)
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Discussion
Fig. 14 dependence of the time ‘tm’ corresponding to ML intensity versus time curve on increasing values of the impact velocity V0 for CaZrO3:Eu3+ phosphor
In the phosphor CaZrO3:Eu3+, it is seen that the ML appears after the impact of load on the phosphor. At first it increases with time, reaches its maximum intensity, a few tenths of a millisecond after the impact, and then it decays. Thus, there ML is caused by the creation of charged surfaces during the impact a piston on the phosphor. The ML intensity increases with time (Fig. 5) because the rate of creation of new surfaces increases with time. The ML intensity gets attains maximum value because the rate of creation of new surfaces is maximum and then intensity decreases with time because the rate of creation of new surfaces decreases. Figures 5 and 7 shows that when phosphor is fractured by impact of a moving piston, then initially the ML intensity increases with time, attain a peak value and later on it decrease with time. Figure 6 show that Im increases with increasing impact velocity Vo. Thus, it seems that rate of creation of new surfaces is directly proportional to the impact velocity
Vo of the piston used to deform. Such findings related are to impact velocity dependence of Im. Figure 7 illustrates that the value of tm decreases with increasing value of impact velocity. It is seen from Fig. 8 that total ML intensity IT initially increases with impact velocity V0 and later on it attains a saturation value. This result indicates that the total area of newly created surfaces initially increases with the impact velocity and then it tends to attain a saturation value, because beyond a particular level, it becomes difficult to create new surfaces in phosphors. Figure 9 shows the ML spectra, In order to investigate the luminescence centres responsible for ML emission, Mechanoluminescence spectrum is recorded. The ML spectra is as similar to the PL spectra, the peak is 612nm (Fig. 9) for ML spectra and 612 for PL spectra (Fig. 10). The intense peak found at 612nm in ML spectra and 613nm for PL spectra both gives the emission in red region. The orange emission peak at
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593nm is missing in ML spectra. This helped us in making estimation that there is an existence of a single emission centre which is because of the transition of Eu3+ ions due to transitions from any of the sublevels of configuration to 5D0 to 7F2 configuration. In Fig. 11, it shows that total ML intensity increases linearly with the mass of phosphor, because with increasing the mass of phosphor number of newly created surfaces increasing thus the area under the curve increases.
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Conclusion 1. ML is excited by the impact velocity of the load dropped on to the phosphors, at first ML intensity increases with time, reach its maximum value and then decreases (Fig. 5). 2. The peak of ML intensity versus time curve increases and shifts towards shorter time value with increasing impact velocity (Fig. 7). 3. For different europium concentration ML intensity increases upto 1.5 mol% then it decreases due to concentration quenching (Figs. 3 and 4). 4. The ML intensity increases linearly with the mass of phosphors (Fig. 11). 5. It is concluded that from above study the information useful for fracture sensor and damage sensor applications.
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References 1. 2.
Chandra BP (1998) Luminescence of Solids. In: Vij DR (ed) . Plenum Press, New York, pp. 361–389 Xu CN, Watanabe T, Akiyama M, Zheng XG (1996) Appl Phys Lett 74:1236
23.
24.
Li CS, Xu CN, Yamada H, Imai Y, Zhang HW, Zhang L (2008) A novel technique for viewing stress distribution with mechanoluminescence materials. Key Eng Mater 368–372:14011404 Chandra BP, Zink JI (1980) Triboluminescence and the dynamics of crystal fracture. Phys Rev B21:816 Kim JS, Kwon YM, Shin N, Sohn KS (2007) Appl Phys Lett 90: 241916 Sage I, Humberstone L, Geddes N, Kemp M, Bishop S, Bourhill G (2001) Smart Mater Struct 10:3312 Dante JG (1983) Reports by the secretary of Army, US Patent. No. 4372211 Aman S, Tomas J (2007) J Materials Sciences 39:5247 J Kaur, V Dubey, NS Suryanarayana. Comparative study of ML and PL spectra of different impurity-doped (Zn, Cd) S mixed phosphors. Res Chem Intermed 39 (9), 4337–4349. J Kaur, NS Suryanarayana, V Dubey. ML Spectra of Gold Doped (Zn, Cd) S Mixed Phosphors. Chalcogenide Letters 7 (5), 329–334 Tiwari Ratnesh, Tamrakar Raunak, Swamy Kumar N, Dubey Vikas. Mechanoluminescence Properties of (Cd0.95Zn0.5)S mixed nanoparticles doped with silver. Ultra Scientist Vol. 26(1)B, 1–6 (2014). Chandra BP, Chandra VK, Mahobia SK, Jha P, Tiwari R, Haldar B (2012) Real-time mechanoluminescence sensing of the amplitude and duration of impact stress. Sensors Actuators A 173:9–16 Ratnesh T, Vikas D, B.P. C (2014) Exact model for the elastico mechanoluminescence of II-VI phosphors. Mat Phys Mech 1(19): 25–38 J Kaur, NS Suryanarayana, V Dubey. Effect of temperature on the ML of Au doped (Zn, Cd) S mixed phosphors. Chin Chem Lett 22 (6), 709–712. Kaur J, Suryanarayana NS, Dubey V, Agrawal S (2011) Spectral characteristics of doped CdS phosphors. Archives of Physics Research 2(4):115–120 Gupta RS, Kaur J, Suryanarayana NS, Dubey V (2010) Int J Nanotech Appl 4(3):185–188 Neha T, Kuraria RK, Kuraria SR (2015) Effect of variable trivalent europium concentration on photo- and thermoluminescence of zirconium dioxide nanophosphors. Mater Sci Semicond Process 31: 214–222 Dubey V, Kaur J, Agrawal S (2014) Effect of europium concentration on photoluminescence and thermoluminescence behavior of Y2O3:Eu3+ phosphor. Res. Chem, Intermed. doi:10.1007/s11164014-1563-3 Vikas Dubey, Jagjeet Kaur, Sadhana Agrawal, N.S. Suryanarayana, KVR Murthy. Effect of Eu3+ concentration on photoluminescence and thermoluminescence behavior of YBO3:Eu3+ phosphor. Superlattice Microst 67: 156–171 (2014). Kaur J, Parganiha Y, Dubey V, Singh D, Chandrakar D (2014) Synthesis, characterization and luminescence behavior of ZrO2: Eu3+, Dy3+ with variable concentration of Eu and Dy doped phosphor. Superlattice Microst 73:38–53 Dubey V, Kaur J, Parganiha Y, Suryanarayana NS, Murthy KVR (2016) Study of formation of deep trapping mechanism by UV, beta and gamma irradiated Eu3+ activated SrY2O4 and Y4Al2O9 phosphors. Appl Radiat Isot 110:16–27 Parganiha Y, Kaur J, Dubey V, Shrivastava R, Dhoble SJ (2016) Synthesis and luminescence study of BaZrO3: Eu3+ phosphor. Superlattice Microst 88:262–270 Kaur J, Shrivastava R, Dubey V, Parganiha Y (2016) Luminescence studies on Ba2MgSi2O7 doped with Eu2+ and Tm3+ phosphors. J Disp Technol 12(5):460–465 Kaur J, Chandrakar D, Dubey V, Shrivastava R, Parganiha Y (2016) Photoluminescence characteristics of dysprosium doped CeO2 phosphor for white light emission. J Disp Technol. doi:10.1109/ JDT.2015.2503330
Author's personal copy J Fluoresc Shrivastava R, Kaur J, Dubey V (2016) White light emission by Dy3+ doped phosphor matrices: a short review. J Fluoresc 26(1):105–111 26. Tiwari N, Dubey V (2016) Luminescence studies and infrared emission of erbium-doped calcium zirconate phosphor. Luminescence 31(3):837–842 27. Parganiha Y, Kaur Saluja J, Dubey V, Shrivastava R (2016) Synthesis and Luminescence properties of Gd2SiO5 phosphor. J Disp Technol 12(1):66–70 28. Parganiha Y, Kaur J, Dubey V, Shrivastava R (2015) YAlO3:Ce3+ powders: synthesis, characterization, thermoluminescence and optical studies. Superlattice Microst 85:410–417 29. Shrivastava R, Kaur J, Dubey V, Jaykumar B (2015) Luminescence studies on europium- and dysprosium-doped di-strontium magnesium silicate phosphor. Res Chem Intermed 41(6):3699–3708 30. Kaur J, Dubey V, Parganiha Y, Singh D, Suryanarayana NS (2015) Review of the preparation, characterization, and luminescence 25.
properties of Pr3+-doped CaTiO3 phosphors. Res Chem Intermed 41(6):3597–3621 31. Kaur J, Singh D, Dubey V, Suryanarayana NS, Parganiha Y, Jha P (2014) Review of the synthesis, characterization, and properties of LaAlO3 phosphors. Res Chem Intermed 40(8):2737–2771 32. Shrivastava R, Kaur J, Dubey V, Jaykumar B (2014) Photoluminescence, trap states and thermoluminescence decay process study of Ca2MgSi2O7: Eu2+, Dy3+ phosphor. Bull Mater Sci 37(4):925–929 33. Dubey V (2012) Thermoluminescence study of Semaria limestone of CG Basin: thermoluminescence and photoluminescence studies of beta irradiated limestone collected from Semaria mines of durg distt. LAP LAMBERT Academic Publishing 34. Kaur J, Parganiha Y, Dubey V, Singh D (2014) A review report on medical imaging phosphors. Res Chem Intermed 40(8):2837–2858
