Production a characterization of new system superconductor TR 3

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1 Journal of Physics: Conference Series PAPER OPEN ACCESS Production a characterization of new system superconductor TR 3 Ba 8 Cu 11 O δ To cite this article: S Sandoval Gutiérrez et al 2016 J. Phys.: Conf. Ser View the article online for updates and enhancements. This content was downloaded from IP address on 20/12/2018 at 18:09

2 Production a characterization of new system superconductor TR 3 Ba 8 Cu 11 O δ S Sandoval Gutiérrez 1, I Supelano G 1, J Roa-Rojas 2 and C A Parra Vargas 1 1 Universidad Pedagógica y Tecnológica de Colombia, Tunja, Boyacá, Colombia 2 Universidad Nacional de Colombia, Bogotá D.C., Colombia. carlos.parra@uptc.edu.co Abstract. The production and structural & magnetic characterization of new superconductor system TR:3811 (TR=Sm, Y, Yb) is presented in this work. The samples were produced by the solid state reaction method. The analysis of the measures of the diffraction X-ray, were made with the Rietveld refinement technique, that allowed to infer that the system presents a Pmm2 type structure with the following lattice parameters (a=3.88å, b=3.82å, c=42.82å). The magnetization measurements were made by using the VSM-VERSALAB equipment with a magnetic field variation from a 100Oe to 7000Oe, and a temperature from 50K to 350K, showing the superconducting transition of the order of 90K. 1. Introduction Since high critical temperature HTSC s superconductors were discovered, a great job has been devoted to raise that temperature of transition between the normal and superconducting state. These HTSC s may present a simple or complex perovskite structure ABOx, according to the amount of strange earth atoms that are arranged in the stoichiometry. One of the earliest and most famous was the compound YBa 2 Cu 3 O 7 (Y123) that exceeded the 90K for Tc [1,9]. At the same time, trying to understand the behaviour of HTSC s, a lot of compounds have been used with different stoichiometric weights and structurally varying the primitive cell of the perovskite. The Y358 occurred subsequently obtaining a Tc of around 94K, with a structure type Pmm2 [6,11]. The amount of oxygen in the superconductor plays a very important role in the creation of Cooper pairs and the anisotropy in the structure increases the Tc. In perovskites type HTcS, the number Barium and rare earth must match the number of copper atoms, in this way, for the TR123 would have TR x-1 Ba x Cu x+1 O y, for TR237 is TR x-1 Ba x Cu 2x+1 O y and so on until getting the formula of TR3811, TR x-5 Ba x Cu x +3 O y [2]. The amount of oxygen must balance the system according to the electronegativity, in the case of TR3811 there are 24 oxygens. With the record of previous studies to the TR3811 structure, two important situations have been observed in the HTSC s, one of them is the relation of the oxygen with the Cooper pairs. Clearly CuO chains present in the CuO 2 provide the Cooper pairs in the superconductivity [15,19]. Furthermore, the more anisotropic the sample is, the more CuO 2 planes in the system, and because of this the aforementioned result. This work shows the superconductor system behaviour TR(3811) with the analysis of magnetization measurements. 2. Experimental The superconducting samples TR 3 Ba 8 Cu 11 O 24 (TR=Y, Yb, Sm), were produced by the solid-state reaction method using commercial oxide precursors with purities of 99.99%. Homogenates compounds were brought to a temperature of 800 C of calcination in a normal atmosphere for 24 hours, and then Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by Ltd 1

3 was compacted under a pressure of 5ton/m 2. The sintering step was performed at 860 o C for 48 hours. Oxygenation was performed between 860 o C and 550 o C, for 24 hours. The samples were analysed with X-ray diffraction (XRD) in an Analytical Expert equipment with Cu-Kα radiation and λ=1,54064å; with values of 2θ between 20 and 90 degrees were made. These diffraction patterns were refined by the Rietveld method using GSAS+EXPGUI code. Magnetization measurements depending on the temperature H(T) for each of the samples of TR:3811 were made in the VSM-VersaLab equipment, with the routine ZFC-ZFC (Zero Field Cooled- Field Cooled) between 50K and 350K and with magnetic fields from 100Oe to 7000Oe. 3. Results and discutions The theoretical structure for compound TR 3 Ba 8 Cu 11 O y (P mm2 ) was shown in Figure 1, with a perovskite type structural arrangement. The difractogramas shows peaks of intensity at 33 and 47, typical of families with these tetragonal structures, as can be seen in the Y237 and Y358 reported by another authors [2,7,13]. Experimental results the XRD on the samples of Sm3811, Yb3811 and Y3811 are shown in Figure 2 in a first view, the samples are not in pure crystalline phase, the peaks at 23, 25, 28, 38, confirm the phases, TR237 and TR358, a result that might interfere with the final temperature of the superconducting state. The Table 1 shows the lattice settings for Tr 3 Ba 8 Cu 11 O 24 (TR=Sm, Yb, Y), in addition to the values of critical temperature. Figure 1. Theoretical diffractogram for the superconductor system Sm3811 by using PCW23. Table 1. Lattice parameters and superconducting critical parameters For samples TR3811 (TR=Sm, Yb, Y). Sample a(å) b(å) c(å) Tc(K) T irr (K) Sm 3 Ba 5 Cu 8 Oδ 3,89 3,821 42, Yb 3 Ba 5 Cu 8 Oδ ,82 42, Y 3 Ba 5 Cu 8 Oδ 3,88 3,82 42,

4 Figure 2. Structural experimental results showing TR3811 (Sm, Yb, Y). In addition, Figures 3 to 5 shows the ZFC-FC magnetization of samples in functions of the temperature. The diamagnetic contribution observed, is characteristic of the superconducting state below Tc. The value of critical temperature, Tc, was determined by the intersection between the linearly extrapolated magnetizations in the normal and superconducting phases and the irreversible temperature, T irr, was determined in the crossing between ZFC and FC curve, the values were obtained with a magnetic field of 500Oe (Table 1). Figures 6 to 8 shows the hysteresis loop at 50K for the three samples, evidencing the characteristic behaviour of superconducting materials of high critical temperatures. Figure 3. Magnetization ZFC-FC curve for TR=Sm Figure 4. Magnetization ZFC-FC curve for TR=Yb Figure 5. Magnetization ZFC-FC curve for TR=Y Figure 6. Hysteresis loop for TR=Y 3

5 Figure 7. Hysteresis loop for TR=Sm Figure 8. Hysteresis loop for TR=Yb. The Table 1 present a summary of the structural and superconducting parameters found. The Yb3811 sample shows a temperature critical higher compared to the other samples. 4. Conclusions The crystal structure has no pure phase. XRD reading shows diffraction peaks related to the structures Y237 and Y358. This mixture of phases does not contribute to a higher Tc, although it exposes the high anisotropy of the sample, as well as the increased of CuO 2 planes. In the magnetization results no higher temperatures of transition, than the ones reported in the sample Y358 by Aliabadi [2]. References [1] Michel Cyrot, Davor Pavuna 1992 Introduction to superconductivity and high Tc materials (Singapore: World Scientific Publishing Co) [2] Aliabdi A, Akhavan F, et all 2009 Physica C [3] Marsh P, Fleming R M, Mandich M L, DeSAntolo A M, Kwo J, Hong M, Martinez Miranda L J 1988 Nature [4] Karpinski J, Rusiecki S, Bucher B, Kaldis E, Jilek E 1989 Physica C [5] Genoud J Y, Graf T, Triscone G, Junod A, Muller J 1992 Physica C [6] Wu K, Ashburn J R, Torng C J, Hor P H, Meng R L, Gao L, Huang Z J, Wang Y Q, Chu C W 1987 Phys Rev Lett [7] Kruaehong T 2014 International Journal Of Physics Sciences [8] Charles P Poole, Horacio A Farach and Richard J Creswick 1995 Superconductivity (Amsterdam: Academic Press) [9] A Tavana and M Akhavan 2010 Eur Phys J B [10] Burns, Gerald 1992 High temperatura superconductivity an introduction (San Diego: Academic Press) [11] D Martinez Buitrago, N C Reyes Suarez, J P Peña, O Ortiz Diaz, J Otalora, C A Parra Vargas 2011 J Supercond Nov Magn (DOI /s x) [12] Tinkham M I 1996 Introduction to superconductivity (New York: Mac-GrawHill) [13] A Schmid 1969 Phys Rev [14] F M Barros, V N Vieira, F W Fabris, M P Cantao, A R Jurelo, P Pureur, J Schaf 2004 Physcica C [15] D V Livanov, A A Varlamov, M Putti, M R Cimberle and C Ferdeghini 2000 Phys J B [16] C A Parra Vargas, D A Landinez Tellez, J Roa-Rojas 2007 Physica B [17] C A Parra Vargas, J Roa-Rojas, D A Landinez Tellez 2006 Revista Colombiana de Física 38 2 [18] C A Parra Vargas, J L Pimente Jr, P Pureur, D A Landinez Tellez, J Roa-Rojas 2009 Physica B [19] Z Hao and J Clem 1991 Phys Rev Lett [20] S Sujinnapramc, P Udomsamuthiruna, T Kruaehonga, T Nilkamjona and S Ratreng 2011 Bull Mat Sci [21] P Udomsamuthirun, T Kruaehong, T Nilkamjon, S Ratreng 2010 J Supercond Nov Magn