| Titre : | Elaboration and characterization of PZT-type ceramics |
| Auteurs : | Aymen Ben Makhlouf, Auteur ; Rachid Makhloufi, Directeur de thèse |
| Type de document : | Thése doctorat |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2023 |
| Format : | 1 vol. (127 p.) / couv. ill. en coul / 30 cm |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Mots-clés: | PZT, Curie temperature, Structural, Morphotropic phase boundary, Dielectric properties, AC conductivity. |
| Résumé : |
In this study, PZT type ceramics with a general formula Pb1-xBax(Zr0.52Ti0.43(Al0.5Sb0.5)0.05)O3 where (x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10) were elaborated by the solid-state reaction method. The main objectives of this study focus on the evolution of structural and electrical properties in the region of the Morphotropic Phase Boundary MPB, the effect of barium substitution, the temperature, and the frequency on electrical properties are also investigated. Different techniques were used to characterize the obtained samples such as X-ray diffraction XRD which shows that the results confirm the high purity of prepared samples without any secondary phase and also indicate the coexistence of both the tetragonal and rhombohedral phases. All the absorption bands corresponding to the perovskite structure are exhibited by The Fourier Transform Infrared spectroscopy FTIR. The Curie temperature TC decreased with increasing Ba2+ content. Furthermore, the effect of the temperature, frequency, and composition on the AC conductivity and dielectric properties demonstrated interesting values |
| Sommaire : |
Dedication . 5 Acknowledgements .. 6 List of figures . 16 List of tables . 19 List of abbreviations 20 General Introduction 22 Chapter I Bibliographic research 25 I.1 Introduction . 26 I.2 Ceramics 26 I.3 Piezoelectric materials . 27 I.3.1 Applications of piezoelectric materials .. 27 I.4 Dielectric materials 28 I.4.1 Ideal dielectrics ... 30 I.4.2 Real Dielectric 30 I.4.2.1 Dielectric constant . 30 I.4.2.2 Dielectric loss . 31 I.4.3 Variables that influence the dielectric constant .. 32 I.4.3.1 Influence of the amplitude of the applied electric field . 32 I.4.3.2 Influence of the frequency . 32 I.4.3.3 Influence of temperature . 32 I.4.3.4 Influence of microstructure .. 33 I.5 Paraelectric materials 34 I.6 Pyroelectric materials 34 I.7 Ferroelectric materials ... 34 I.7.1 Classical ferroelectric .35 I.7.2 Relaxer ferroelectric 35 I.8 Physical properties of ceramics materials ....... 35 I.8.1 Piezoelectricity . 36 I.8.2 Pyroelectricity 36 I.8.3 Ferroelectricity . 37 I.8.4 Hysteresis cycle 37 I.8.5 Dielectricity 38 I.8.6 Curie temperature . 38 I.8.7 Impedance spectroscopy 38 I.8.7.1 Nyquist plot .. 40 I.8.7.2 Bode plot I.9 Different types of polarization ... 41 I.9.1 Space charge polarization (Pc) ... 42 I.9.2 Dipole polarization (Pd) 42 I.9.3 Atomic or ionic polarization (Pa) ... 43 I.9.4 Electronic polarization (Pe) . 43 I.10 Perovskite structure 44 I.10.1 Classification of the perovskite structure ..... 44 I.10.1.1 Simple perovskite ........... 44 I.10.1.2 Complex perovskite ....... 45 I.10.2 Stability of the perovskite structure .......... 45 I.10.2.1 Electro-neutrality condition .... 45 I.10.2.2 Ionicity of the bonds ........ 45 I.10.2.3 Tolerance factor ....... 46 I.11 Applications of perovskite materials ... 4613 I.11.1 Electricals applications ........ 46 I.11.2 Catalytic Applications 47 I.11.3 Conductor . 47 I.12 Lead Zirconate Titanate (PZT) . 47 I.12.1 Overview of the selected material . 47 I.13 Morphotropic phase boundary .... 48 I.14 Effect of doping on the properties of PZT materials . 49 I.14.1 Isovalent dopants . 49 I.14.2 Donor dopants ... 49 I.14.3 Acceptor dopants . 50 Chapter II Experimental part ....... 52 II.1 Introduction . 53 II.2 Solid-state reaction method II.3.1 Precursor . 54 II.3.1.1 Lead monoxide PbO: ... 54 II.3.1.2 Zirconium dioxide ZrO2......... 55 II.3.1.3 Titanium dioxide TiO2: ... 55 II.3.2 Dopants .. 56 II.3.2.1 Al2O3: 56 II.3.2.2 Sb2O3: 57 II.3.2.3 BaCO3: 57 II.4 Elaboration process 57 II.4.1 Weighing and mixing 59 II.4.2 Grinding . 59 II.4.3 Calcination: . 5914 II.4.4 The shaping of a pellets ... 60 II.4.5 The sintering . 61 II.5 Characterization technique: .. 62 II.5.1 XRD Analyses 62 II.5.2 Scanning electron microscopy SEM ... 64 II.5.3 Fourier Transform Infrared Spectroscopy FTIR ........ 64 II.5.4 Density .. 65 II.5.5 Impedance spectroscopy measurement ... 66 Chapter III Structural and Microstructural properties of PZT-based ceramics .................... 68 III.1 Introduction . 69 III.2 Structural properties .. 70 III.3 Morphotropic phase boundary . 73 III.4 Lattice parameter . 77 III.5 Tolerance factor 79 III.6 Fourier Transform Infrared spectroscopy (FTIR) .... 81 III.7 Density .. 82 III.7.1 Effect of temperature on density ............... 82 III.7.2 Effect of barium substitution on density .......... 83 III.8 Microstructural analysis ...... 84 III.8.1 Effect of Barium substitution on average grain size ... 86 III.9 Energy dispersive spectrometric analysis (EDS) ....... 86 III.10 Conclusion . 89 Chapter IV Effect of Barium substitution and various parameters on impedance spectroscopy and electrical properties of PZT based ceramics .. 90 IV.1 Introduction 91 IV.2 Dielectric studies 92 IV.2.1 Dielectric constant and dielectric loss ...... 9215 IV.2.1.1 The effect of temperature . 92 IV.2.1.2 The effect of Frequency .. 93 IV.2.1.3 The effect of Barium substitution 95 IV.3 Curie temperature . 96 IV.4 Impedance spectroscopy ...... 96 IV.4.1 Nyquist plot ...... 96 IV.4.1.1 The effect of temperature and frequency on electrical properties .............. 97 IV.4.2 Bode plots ...... 100 IV.4.2.1 The Real Part .............. 100 IV.4.2.2 The Imaginary Part ....... 102 IV.5 AC conductivity 104 IV.5.1 The evolution of AC conductivity as function of temperature . 104 IV.5.2 The evolution of AC conductivity as function frequency 106 IV.5.3 The Barium effect on AC conductivity 108 IV.6 Conclusion 109 General conclusion 110 References . 114 Annexes 127 |
| Type de document : | Thése doctorat |
| En ligne : | http://thesis.univ-biskra.dz/6197/ |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| TCH/105 | Théses de doctorat | bibliothèque sciences exactes | Consultable |
