Engineering and Technology Journal Vol. 37, Part B, No. 1, 2019 DOI: http://dx.doi.org/10.30684/etj.37.1B.4 Mojahid M. Najim Preparation and Study the Structure of Pure Department of Applied 4+ Sciences, University of and Impure with Zr Ion Technology. Baghdad.

Iraq. 4+ [email protected] Abstract: In this research, pure and impure barium titanate with Zr ion with two molar ratios x= (5, 10) % have been synthesized by solid-state reaction technique. ° ° Wasan A. Hekmat The powders calculations at two temperatures (950 C and 1400 C). An XRD technique was used in order to study the of pure and impure Department of Applied barium titanate, which confirmed the formation of the tetragonal phase of BaTiO3, Sciences, University of then calculate the lattice parameters of pure and impure barium titanate, the Technology. Baghdad. addition of zirconium ion Zr4+ lead to increases lattice parameters. Iraq. Keywords: Barium titanate, Ferroelectric, Piezoelectric, X-ray diffraction.

Received on: 06/03/2018 Accepted on: 25/06/2018 Published online: 25/04/2019 How to cite this article: M.M. Najim and W.A. Hekmat, “Preparation and Study the Structure of Pure and Impure Barium Titanate with Zr4+ Ion,” Engineering and Technology Journal, Vol. 37, Part B, No. 1, pp. 21-24, 2019.

1. Introduction Barium titanate has been used in wide application such as and multilayer capacitors (MlCS) [1,2], PTC , piezoelectric transducers, variety of electro-optic devices and integral capacitors in printed circuit boards (PCB). BaTiO3 is also a semiconducting and non- linear optical material when doped with other elements, and therefore can be used for resistors with a positive temperature coefficient Figure 1: Barium Titanate Structure [5] of resistivity [3].

2. Barium titanate Phase transformations

Barium titanate BaTiO3 has a structure 2+ 4+ with formula A B O3, where A is the large cation which is located at eight corners, B is the small cation located in the body center and oxygen atoms in the face center [4] as shown in Figure 1. It has a wide application because of its ferroelectric and piezoelectric properties. Barium titanate has four-phase transition depend in temperature (cubic, tetragonal, orthorhombic and Figure 2: Phase transformations of pure BaTiO3 vs. rhombohedra) [6]. Cubic phase, this phase occur temperature [7]. above (120°C) and have a spontaneous random polarization. In this 3. Experimental temperature range, (120 °C) Ti4+ ion lies in the Pure and impure barium titanate was synthesized center of the structure. Tetragonal phase, its via solid-state reaction, pure barium titanate ferroelectric and stable phase between (BaTiO3)(BT) was synthesized by mixing raw ° ° (5 C

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milling and grinding for 24h, drying the mixture Ti4+ ion instead Zr4+ ion. The crystal structure at 80°C for 15h to get rid of alcohol, calcinations was studied to all powders were synthesized (BT) the powder at two temperature (950°C and and (BZT) using X-ray diffraction with Cu target 1400°C) for four hours. and wavelength 1.54 Å, operating at (40Kv), Impure barium titanate (BZT) as the same steps (30mA) and the samples were scanned from (20- as above, impure barium titanate synthesized by 60°2θ) with scan speed (8deg/min). Figure 3 mixing raw materials BaCO3 and TiO2 and shows the flow chart of synthesized pure and additive of (5%, 10%) of zirconium ZrO2 to impure barium titanate. prepare (BZT) (BaTi1-xZrxO3) by substitution of

Formation of Pure Formation of impure BaTiO3 (BT) BaTiO3 (BZT)

High Purity (98%) Barium High Purity (98%) Barium Carbonate BaCO 3 Carbonate BaCO3

High Purity (98%) High Purity (98%) Titanium Oxide TiO2 Titanium Oxide TiO2

High purity (98%) Zirconium Oxide ZrO2

Ethanol Alcohol (96%) (C2H 5OH)

Drying the mixture at 80°C for 15h

Calcinations the powder at two temperature 950°C and 1400°C

Study the structure of all powders using XRD, Calculate lattice parameter (a,b,c) [Dicvol program, Fullprof Program, WinPLOTR Program]

Figure 3: Flow Chart of synthesized pure (BT) and impure (BZT).

4. Result and Discussion carbonate no. (00-005-0378) and standard of I. X-ray diffraction of raw material TiO2 no. (00-021-1272). Fig. 4 refers to the XRD pattern of raw materials BaCO3 and TiO2 before calcinations this pattern matched with the standard pattern of barium

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to substitute (Zr4+) ions instead of (Ti4+) ions on the (A) sites of the BaTiO3 lattice. This is because 600 of the ionic radius of zirconium ion (Zr4+) (0.72 500 4+ 400 Å) is Larger as compared to titanium ion (Ti ) BaCO3 300 TiO2 (0.60 Å) [12].

Intensity(a.u.) 200

100 1600

0 1400 (101) (110) 0 10 20 30 40 50 60 70 80 90 2 Theta (degree) 1200 (111) 1000

Figure 4: XRD patterns for Barium Carbonate 800 (002) (200) (112) (211) BaCO3 and Titanium oxide TiO2 befor calcinations 600 (201) (001) (100) (102) (210) Intensity(a.u.) 400 (111) (112) (211) 100 (002) (200) 200 (001) ( ) (101) (110) (201) II X-ray diffraction of pure BaTiO3 (BT). * (102) (210) 0 Figure 5 X-ray diffraction pattern confirmed the 0 10 20 30 40 50 60 70 2θ (degree) existence of the barium titanate with tetragonal . phase (the pattern matched with the standard Figure 5: XRD patterns for pure barium titanate pattern JCPDS no 05-0626). At 950°C (a) at 950°C and (b) at 1400°C temperature, there was a low intensity of TiO2 (Titanium Dioxide) but there was no BaCO3 Pure BaTiO3+5%,10%Zr at 950C (Barium Carbonate). The symbol * show the 2500 peaks for the (TiO2) titanium dioxide this means not the complete reaction of formation of barium 2000 titanate because of the present of another peak 1500 belong to TiO2 [8]. 1000 10% Zr ° At (1400 C) temperature there was no residual Intensity(a.u.) 500 5% Zr material detected by XRD technique indicated to 0 Pure BaTiO3 complete reaction, this reaction appears high 20 30 40 50 60 70 80 resolution in 2θ position for peaks indicated to a Diffraction2θ (degree Angle) good crystallinity and formation of pure barium Figure 6: XRD for BaTiO3 with additives ZrO2 titanate (BaTiO3). So it can be seen diffraction (5% , 10% ) at 950°C. peaks at 2θ=44.950°, 45.379°, 50.704°,50.998°, ° ° ° 51.096 , 56.018 , 56.293 , are widened gradually 2500 and lastly split during an increase in the calcinations temperature. This phenomenon refers 2000

to the (tetragonal structure) of barium titanate 1500 (BaTiO3) phase was formed well with increases

1000 10% Zr in calcinations temperature [9].

Intensity(a.u.) 5% Zr 500

III X-ray diffraction of impure barium titanate Pure BaTiO3 (BZT) 0 20 25 30 35 40 In this part additive zirconium oxide ZrO2 to the 2θ (degree. ) barium titanate with two molar ratios (5%, 10%) calcinations at two temperature (950°C and Figure 7: The shifted of the first three peaks of 1400°C) then study the structure of barium (BZT) at 950°C. titanate using x-ray diffraction after this additive, the additives of ZrO2 to barium titanate lead to Pure BaTiO3+5% ,10% Zr at 1400

change from tetragonal phase to cubic phase at 3000 ° 1400 C and an increase in lattice parameters [10], 2500

this is a clear refers to the addition of Zr lead to 2000

disorder in the barium titanate structure[11]. 1500

X-ray technique show change in peak position as 1000 Intensity(a.u.) 10% Zr compared to pure barium titanate. So it can be 500 5% Zr 4+ seen that with (Zr ) substitution in barium Pure BaTiO3 0 titanate, the (2θ) peaks shifted towards lower 20 30 40 50 60 70 80 90 2θ (degree ) angle side refers to the increase in lattice parameter, as shown in Figures 6-9 This indicates Figure 8: XRD for BaTiO3 with additives ZrO2 (5% , 10% ) at 1400°C

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undergo shifted toward lower angle because of the doped of (Zr4+) ion (0.72 Å) which is smaller 3000 4+ than (Ti ) ion (0.60 Å) in the (A) sites of BaTiO3 2500 and this refers to increase in lattice parameters, 2000 calculation of lattice parameter appears matched 1500 with X-ray diffraction. 1000 10% Zr Intensity(a.u.) 500 5% Zr References Pure BaTiO3 0 20 25 30 35 40 [1] Y. Dang-Hyok, “Tetragonality of barium titanate 2θ (degree. ) powder for a application,” Journal of Figure 9: The shifted of the first three peaks of Ceramic Processing Research, Vol.7, No. 4, p. 343- (BZT) at 1400°C 354, 2006. [2] H. Lin, “Structure and Properties of IV. Lattice parameters Perovskite- Barium Titanate (BaTiO3),” Ph.D. Theses, Calculation the lattice parameters using (Dicvol San Jose State University, 2002. Program, Fullprof Program, WinPLOTR [3] S.M. Ali and M.M. Najim, “Synthesis and Study Program) for pure and impure barium titanate the Dielectric Properties of La-Doped and Undoped with two molar ratio x= (5, 10) %, at two Barium Titanate Nanopowders,” Journal of Eng. & temperature 950°C and 1400°C. Table 1 and 2 Tech., Vol. 33, No. 2, 2015. show the lattice parameters of pure and impure [4] S. Pradhan and G.S Roy, “Study the Crystal barium titanate. Structure and Phase Transition of BaTiO3 – A Pervoskite,” J. Researcher Vol. 5, No. 3, p.63-67, ° 2013. V. Lattice parameter of pure BaTiO3 at 950 C and 1400°C. [5] M.M. Najim, “Synthesis and study the structural and physical properties of Nano-BaTiO Ph.D. Table 1 show lattice parameter of the tetragonal 3,” ° Thesis, University of Technology, School of Applied phase of pure (BT) calcinations at 950 C and Sciences, 2013. 1400°C respectively. [6] R. Blinc, “Order and Disorder in and Relaxor Ferroelectrics,” Struct. Bond, Vol.124, p. 51- Table 1: Lattice parameter of Pure BaTiO3 (BT) 67, 2007. Calcinations Temp. a=b(Å) c(Å) [7] J.P.H. Laraa, M.P.Labraa, F.R.B.Hernándeza, 950°C 3.9912 4.0167 J.A.R. Serranob, E.O.Á. Dávilac, P. Thangarasud, 1400°C 3.9939 4.0300 A.H. Ramirezb, “Structural Evolution and Electrical 3+ Properties of BaTiO3 Doped with Gd ,” Materials Research, 2017. VI. Lattice parameter of impure BaTiO3 (BZT) at 950°C and 1400°C. [8] M.C. de Andrade, G.N. Carneiro, L.M. Elizabeth, At 950°C for both ratios (5%, 10%) mol of additives C. A.Jorge, “Synthesis and Characterization of Barium Titanate by Solid-State Reaction,” Materials Science of zirconium ion in barium titanate, x-ray analysis Forum, Vol. 802, p. 285-290, 2014. Figure 6 show the tetragonal phase of barium titanate, at 1400°C Zr ion lead to disorder in the [9] N.M. Zali, C.S. Mahmood, S.M. Mohamad, C.T. Foo, and J. A.Murshidi, “X-ray Diffraction Study of barium titanate structure and lead to change from Crystalline Barium Titanate ,” AIP tetragonal phase to cubic phase and an increase in Conference Proceedings, Vol.1584, No.160, 2014. lattice parameters. As shown in Table 2. [10] K.E. Oksuz, S. Sen and U. Sen, “Influence of

ZrO2 Addition on the Structure and Dielectric Table 2: Lattice parameter of impure BaTiO3 Properties of BaTiO3 Ceramics,” Special Issue of the (BZT) 6th International Congress & Exhibition, Calcinations a=b(Å) c(Å) Vol.131, 2017. Temp. 5% 10% 5% 10% [11] A.E.H. Elbasset, T. Lamcharfi, F. Abdi, 1400°C 4.0122 4.0304 4.0122 4.0304 S. Sayouri, L. Mrharrab and Z. Mohamed, “Characterization of zirconium barium titanate powders by Ramman spectroscopy,” International Conclusion Journal of Current Research, Vol. 8, p.25281-25284, In this study we observed pure barium titanate 2016. with tetragonal phase has been found at (1400°C) that means it formed at high temperature, the [12] S. Mahajan, O.P Thakuri, C. Prakash, K. Sreenivas, “Effect of Zr on dielectric, ferroelectric and additives of ZrO2 to barium titanate lead to impedance properties of BaTiO3 ceramic,” Bull. change from tetragonal phase to cubic phase and Mater. Sci., Vol. 34, No. 7, p.1483–1489, 2011. increase in lattice parameters. Diffraction peaks

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