Surface functionalization of BiFeO₃: A pathway for the enhancement of dielectric and electrical properties of poly(methyl methacrylate)--BiFeO₃ composite films

Abstract

A novel two-phase composite film is prepared by the solvent casting method employing poly(methyl methacrylate) (PMMA) as polymer matrix and bismuth ferrite (BFO) as ceramic filler. The surfaces of BFO are functionalized by proper hydroxylating agents to activate their chemical nature. The structural analysis of the composite films confirms that the composites made up of functionalized BFO (BFO-OH) have a distorted rhombohedral structure. The morphological analysis shows that BFO-OH particles are equally distributed over the polymer matrix. The −OH functionality of BFO-OH is confirmed by FTIR. The dielectric and electrical studies at a frequency range from 100 Hz to 1 MHz reveal that PMMA–(BFO-OH) composites have enhanced dielectric constant as well as electrical conductivities, much higher than that of unmodified composites. According to the ferroelectric measurement result, the hydroxylated composite film shows a superior ferroelectric behavior than that of the unmodified one, with a remanent polarization (2P_r) of 2.764 μC/cm².

Keywords

functionalized bismuth ferrite / composites / AC electrical conductivity / dielectric properties

References

[1] Yuan J K, Li W L, Yao S H, . High dielectric permittivity and low percolation threshold in polymer composites based on SiC-carbon nanotubes micro/nano hybrid. Applied Physics Letters, 2011, 98(3): 032901

[2] Vishnuvardhan T K, Kulkarni V R, Basavaraja C, . Synthesis, characterization and a.c. conductivity of polypyrrole/Y₂O₃ composites. Bulletin of Materials Science, 2006, 29(1): 77–83

[3] Sava F, Cristescu R, Socol G, . Structure of bulk and thin films of poly(methyl methacrilate (PMMA) polymer prepared by pulsed laser deposition. Journal of Optoelectronics and Advanced Materials, 2002, 4(4): 965–970

[4] Grossiord N, Loos J, Koning C E, . Strategies for dispersing carbon nanotubes in highly viscous polymers. Journal of Materials Chemistry, 2005, 15(24): 2349–2352

[5] Arbatti M, Shan X, Cheng Z Y, . Ceramic–polymer composites with high dielectric constant. Advanced Materials, 2007, 19(10): 1369–1372

[6] Stefanescu E A, Tan X, Lin Z, . Multifunctional PMMA–ceramic composites as structural dielectrics. Polymer, 2010, 51(24): 5823–5832

[7] Wang H, Xiang F, Li K, . Ceramic–polymer Ba_0.6Sr_0.4TiO₃/poly(methyl methacrylate) composites with different type composite structures for electronic technology. Applied Ceramic Technology, 2010, 7(4): 435–443

[8] Khattari Z, Maghrabi M, McNally T, . Impedance study of polymethyl methacrylate composites/multi-walled carbon nanotubes (PMMA/MWCNTs). Physica B: Condensed Matter, 2012, 407(4): 759–764

[9] Jung S, Baeg K, Yoon S, . Low-voltage-operated top-gate polymer thin-film transistors with high capacitance poly(vinylidene fluoride-trifluoroethylene)/poly(methyl methacrylate) dielectrics. Journal of Applied Physics, 2010, 108(10): 102810

[10] Ahlawat A, Satapathy S, Bhartiya S, . BiFeO₃/poly(methyl methacrylate) nanocomposite films: A study on magnetic and dielectric properties. Applied Physics Letters, 2014, 104(4): 042902 (3 pages)

[11] Fiebig M, Lottermoser T, Fröhlich D, . Observation of coupled magnetic and electric domains. Nature, 2002, 419(6909): 818–820

[12] Loh K J, Chang D. Zinc oxide nanoparticle-polymeric thin films for dynamic strain sensing. Journal of Materials Science, 2011, 46(1): 228–237

[13] Setvín M, Daniel B, Mansfeldova V, . Surface preparation of TiO₂ anatase (101): Pitfalls and how to avoid them. Surface Science, 2014, 626: 61–67

[14] Beier C W, Cuevas M A, Brutchey R L. Effect of surface modification on the dielectric properties of BaTiO₃ nanocrystals. Langmuir, 2010, 26(7): 5067–5071

[15] Kim P, Jones S C, Hotchkiss P J, . Phosphonic acid-modified barium titanate polymer nanocomposites with high permittivity and dielectric strength. Advanced Materials, 2007, 19(7): 1001–1005

[16] Song Y, Shen Y, Liu H Y, . Improving the dielectric constants and breakdown strength of polymer composites: effects of the shape of the BaTiO₃ nanoinclusions, surface modification and polymer matrix. Journal of Materials Chemistry, 2012, 22(32): 16491–16498

[17] Chon J, Ye S, Cha K J, . High-dielectric sol–gel hybrid materials containing barium titanate nanoparticles. Chemistry of Materials, 2010, 22(19): 5445–5452

[18] Li J, Claude J, Norena-Franco L E, . Electrical energy storage in ferroelectric polymer nanocomposites containing surface-functionalized BaTiO₃ nanoparticles. Chemistry of Materials, 2008, 20(20): 6304–6306

[19] Chu L W, Prakash K N, Tsai M T, . Dispersion of nano-sized BaTiO₃ powders in nonaqueous suspension with phosphate ester and their applications for MLCC. Journal of the European Ceramic Society, 2008, 28(6): 1205–1212

[20] Sharma S, Tomar M, Kumar A, . Multiferroic properties of BiFeO₃/BaTiO₃ multilayered thin films. Physica B: Condensed Matter, 2014, 448: 125–127

[21] Lee M H, Lee S C, Sung Y S, . Improvement of ferroelectric and leakage current properties with Zn–Mn co-doping in BiFeO₃ thin films. Ferroelectrics, 2010, 401(1): 186–191

[22] Godara S, Sinha N, Ray G, . Combined structural, electrical, magnetic and optical characterization of bismuth ferrite nanoparticles synthesized by auto-combustion route. Journal of Asian Ceramic Societies, 2014, 2(4): 416–421

[23] Xie L, Huang X, Huang Y, . Core@double-shell structured BaTiO₃–polymer nanocomposites with high dielectric constant and low dielectric loss for energy storage application. The Journal of Physical Chemistry C, 2013, 117(44): 22525–22537

[24] Paniagua S A, Kim Y, Henry K, . Surface-initiated polymerization from barium titanate nanoparticles for hybrid dielectric capacitors. ACS Applied Materials & Interfaces, 2014, 6(5): 3477–3482

[25] Bajpai O P, Kamdi J B, Selvakumar M, . Effect of surface modification of BiFeO₃ on the dielectric, ferroelectric, magneto–dielectric properties of polyvinylacetate/BiFeO₃ nanocomposites. Express Polymer Letters, 2014, 8(9): 669–681

[26] Ray D K, Himanshu A K, Sinha T P, . Structural and low frequency dielectric studies of conducting polymer nanocomposites. Indian Journal of Pure and Applied Physics, 2007, 45: 692–699

[27] Tripathi S K, Gupta A, Kumari M, . Studies on electrical conductivity and dielectric behaviour of PVdF–HFP–PMMA–NaI polymer blend electrolyte. Bulletin of Materials Science, 2012, 35(6): 969–975

[28] Zhao R, Zhao J, Wang L, . Reduced sedimentation of barium titanate nanoparticles in poly(vinylidene fluoride) films during solution casting by surface modification. Journal of Applied Polymer Science, 2015, 132(42): 42662

[29] Prakash B S, Varma K B R. Dielectric behavior of CCTO/epoxy and Al-CCTO/epoxy composites. Composites Science and Technology, 2007, 67(11–12): 2363–2368

[30] Sengwa R J, Choundhary S, Sankhla S. Dielectric properties of montmorillonite clay filled poly(vinyl alcohol)/poly(ethylene oxide) blend nanocomposites. Composites Science and Techno-logy, 2010, 70(11): 1621–1627

[31] Catalan G, Scott J F. Physics and applications of bismuth ferrite. Advanced Materials, 2009, 21(24): 2463–2485

[32] Luther G. Dielectric dispersion of ferroelectric triglycine sulphate in the microwave region. Physica Status Solidi A: Applied Research, 1973, 20(1): 227–236

[33] Thakur V K, Tan E J, Lin M F, . Poly(vinylidene fluoride)-graft-poly(2-hydroxyethyl methacrylate): a novel material for high energy density capacitors. Journal of Materials Chemistry, 2011, 21(11): 3751–3759

[34] Jayalakshmi M, Balasubramanian K. Simple capacitors to supercapacitors- an overview. International Journal of Electrochemical Science, 2008, 3: 1196–1217

[35] Rajalakshmi R, Kambhala N, Angappane S, . Enhanced magnetic properties of chemical solution deposited BiFeO₃ thin film with ZnO buffer layer. Materials Science and Engineering B, 2012, 177(11): 908–912

[36] Ramesh S, Liew C W, Arof A K. Ion conducting corn starch biopolymer electrolytes doped with ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate. Journal of Non-Crystalline Solids, 2011, 357(21): 3654–3660

[37] Park J H, Hwang D K, Lee J, . Studies on poly(methyl methacrylate) dielectric layer for field effect transistor: Influence of polymer tacticity. Thin Solid Films, 2007, 515(7–8): 4041–4044

[38] Gravatt C C, Gross P M. Effect of hydrogen bonding on the electrical conductivity of organic solids. Journal of Chemical Physics, 1967, 46(2): 413

[39] Singh V R, Dixit A, Garg A, . Effect of heat treatment on the structure and properties of chemical solution processed multiferroic BiFeO₃ thin films. Applied Physics A: Materials Science & Processing, 2008, 90(1): 197–202

Acknowledgements

We would like to express our sincere thanks to Sambalpur University for providing the facilities for research works. We are also thankful to NIT Raipur for providing the facilities of XRD & SEM study and University Grant Commissions (UGC) (F. No: 42-277/2013) (SR), New Delhi, Government of India, for the financial support.

RIGHTS & PERMISSIONS

2017 Higher Education Press and Springer-Verlag Berlin Heidelberg