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Physical and piezoelectric properties of ceramics in the (K0.5Na0.5)NbO3–Bi(Zn0.5Ti0.5)O3–PbTiO3 system
(2018-01-01)
Prasatkhetragarn, Anurak
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Phetphum, Natthaporn
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Bongkarn, Theerachai
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Vittayakorn, Naratip
;
Maensiri, Santi
Piezoelectric ceramic materials in xKNN–yBZT–(1-x-y)PT system, when both of x and y were varied from 0.05 to 0.20, were prepared by a solid state reaction technique. Phase formation, microstructure, density, ferroelectric and piezoelectric properties of the specimens were investigated. The powders were calcined and sintered at the temperature of 900 oC for 6 h and 1050 oC for 2 h, respectively, to obtain single phase perovskite structures. The results indicated that the crystal structure of xKNN–yBZT–(1-xy)PT ceramics system changed from tetragonal to monoclinic phase while the secondary phase of PbTi2O7 was present at the composition of point 5 (0.2KNN–0.1BZT–0.7PT). The densities of the specimens tended to decrease with increasing KNN content. However, the densities and average grain sizes of their ceramics increased with increasing BZT content. In addition, the maximum values of piezoelectric and ferroelectric properties were achieved in 0.05KNN–0.05BZT–0.9PT compound, likely caused by the grain size effects.
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Local structure, electrical and magnetic properties of Fe-doped Sr2(Ni,Mo)O6 double perovskite
(2017-08-01)
Prasatkhetragarn, Anurak
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Sriboonpeng, Chana
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Jantaratana, Pongsakorn
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Vittayakorn, Naratip
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Thammajak, Nirawat
Double perovskite material of 10 mol% Fe-doped Sr<inf>2</inf>(Ni,Mo)O<inf>6</inf> was prepared by solid-state reaction. The NiMoO<inf>4</inf> precursor was first synthesized as a starting material with calcination temperature at 1100 °C in air. Effects of FeO, Fe<inf>2</inf>O<inf>3</inf> and Fe<inf>3</inf>O<inf>4</inf> dopant on phase formation, morphology, electrical and magnetic properties of the specimens were investigated and discussed. The XRD technique was used to analyze the phase formation of the samples. It can be clearly seen that phase formation of pure Sr<inf>2</inf>(Ni,Mo)O<inf>6</inf> indicated the cubic phase structure, while the tetragonal phase was found with FeO, Fe<inf>2</inf>O<inf>3</inf> and Fe<inf>3</inf>O<inf>4</inf> dopant. All XANES spectra were collected at the ambient temperature and atmospheric pressure. The result demonstrated that the oxidation state of Fe is 3<sup>+</sup>, indicating the occurrence of γ-Fe<inf>2</inf>O<inf>3</inf> phase for all samples. In addition, the room temperature ferroelectric and ferromagnetic properties were determined using a simple Sawyer–Tower circuit (at fixed measuring frequency of 50 Hz) and Vibrating Sample Magnetometer (VSM), respectively. The maximum ferroelectric and ferromagnetic properties were seen with Fe<inf>2</inf>O<inf>3</inf> dopant. Interestingly, the ferroelectric and ferromagnetic properties of Sr<inf>2</inf>(Ni,Mo)<inf>0.9</inf>Fe<inf>0.1</inf>O<inf>6</inf> ceramics were affected by iron oxide doping.
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Ferroelectromagnetic characteristic of Na-doped 0.75BiFeO 3-0.25BaTiO3 multiferroic ceramics
(2013-05-01)
Prasatkhetragarn, Anurak
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Arthan, Ammaruta
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Jantaratana, Pongsakorn
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Vittayakorn, Naratip
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Yotburut, Benjaporn
BiFeO<inf>3</inf>-based materials are expected to have both ferroelectricity and ferromagnetism simultaneously. In this study, effects of Na-doping (0.5, 1.0, 3.0, and 5.0 mol%) on ferromagnetic and ferroelectric properties of 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> ceramics which have been fabricated by the solid state reaction technique are studied. The effects of Na-doped 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> ceramics on the crystal structure, and magnetic and electrical properties were investigated and discussed. Rhombohedrally distorted 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> showed weak ferromagnetic and ferroelectric properties. In addition, ferroelectric and ferromagnetic properties of 0.75BiFeO<inf>3</inf>-0. 25BaTiO<inf>3</inf> have been controlled by Na doping, and the maximum values of magnetization and polarization were observed at 5.0 mol%. © 2012 Elsevier Ltd and Techna Group S.r.l.
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Investigation on ferromagnetic and ferroelectric properties of (La, K)-doped BiFeO3-BaTiO3 solid solution
(2013-05-01)
Prasatkhetragarn, Anurak
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Muangkonkad, Pantip
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Aommongkol, Parichart
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Jantaratana, Pongsakorn
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Vittayakorn, Naratip
Multiferroic materials of BiFeO<inf>3</inf>-BaTiO<inf>3</inf> solid solution have been fabricated in order to improve ferromagnetic and ferroelectric properties. The effects of La (1 mol%) and K (varied from 0.5-5 mol%) doped 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> on phase formation, ferromagnetic and ferroelectric properties have been investigated and discussed. The rhombohedral perovskite phase of specimens was characterized by XRD technique. Fracture morphology reveals the grain growth characteristics with increasing K content. (La, K)-doped 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> with La=1 mol% and K=3 mol% exhibits the highest remnant polarization and remnant magnetization. © 2012 Elsevier Ltd and Techna Group S.r.l.
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Phase transitions and dielectric properties in Bi(Zn1/2Ti 1/2)O3-(Na1-yLiy)NbO3 perovskite solid solutions
(2009-03-01)
Huang, Chien Chih
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Vittayakorn, Naratip
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Prasatkhetragarn, Anurak
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Gibbons, Brady J.
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Cann, David P.
Perovskite solid solutions based on the system Bi(Zn<inf>1/2</inf>Ti <inf>1/2</inf>)O<inf>3</inf>-NaNbO<inf>3</inf> were obtained via solid-state processing techniques. The crystal structure and ferroelectric phase transitions were studied by means of X-ray diffraction and dielectric measurements. A stable perovskite phase was obtained for Bi(Zn<inf>1/2</inf>Ti <inf>1/2</inf>)O<inf>3</inf> substitutions up to 10mol%. The dielectric characterization revealed that as the Bi(Zn<inf>1/2</inf>Ti<inf>1/2</inf>)O <inf>3</inf> content increased, the transition temperature decreased and the transition peak became very diffuse. The polarization hysteresis loop and strain measurements presented evidence of an induced ferroelectric phase with 1 mol % Bi(Zn<inf>1/2</inf>Ti<inf>1/2</inf>)O<inf>3</inf> substitutions. The planar coupling factor (k<inf>p</inf>) for 0.01Bi(Zn<inf>1/2</inf>Ti <inf>1/2</inf>)O<inf>3</inf>-0.99NaNbO<inf>3</inf> was measured to be 0.28. In addition, with the substitution of Li for Na in the Bi(Zn<inf>1/2</inf>Ti <inf>1/2</inf>)O<inf>3</inf>-(Na<inf>1-y</inf>Li<inf>y</inf>)NbO<inf>3</inf> system, the diffuseness of the transition peak decreased and the transition temperature increased. © 2009 The Japan Society of Applied Physics.
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Synthesis and properties of Pb(Co1/3Nb2/3)O3 ceramics
(2008-10-20)
Unruan, Muangjai
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Vittayakorn, Naratip
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Wongmaneeruang, Rewadee
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Prasatkhetragarn, Anurak
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Ananta, Supon
In this study, Pb(Co<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> or PCN ceramics have been produced by sintering PCN powders synthesized from lead oxide (PbO) and cobalt niobate (CoNb<inf>2</inf>O<inf>6</inf>) with an effective method developed for minimizing the level of PbO loss during sintering. Attention has been focused on relationships between sintering conditions, phase formation, density, microstructural development, dielectric and ferroelectric properties of the sintered ceramics. The densities of sintered PCN ceramics increased with increasing sintering temperature. However, it was observed that at too high temperature the density began to decrease. Change of dielectric properties with sintering temperature also followed the same trend as the density. Based on X-ray diffraction analysis, density data, SEM micrograph, and dielectric properties, the optimum sintering temperature for a high purity PCN ceramic was found to be about 1100 and 1150 °C. A strongly diffused dielectric peak also showed a typical characteristic of ferroelectric relaxors. The P-E hysteresis loops observed at -70 °C were of slim-loop type with small remnant polarization values, which confirmed relaxor ferroelectric behavior of PCN ceramics. © 2007 Elsevier B.V. All rights reserved.
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Synthesis and dielectric and ferroelectric properties of ceramics in (1 - X)Pb(Zr1/2Ti1/2)O3-(x)Pb(Co 1/3Nb2/3)O3 system
(2008-02-15)
Prasatkhetragarn, Anurak
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Vittayakorn, Naratip
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Ananta, Supon
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Yimnirun, Rattikorn
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Cann, David P.
Ceramics in a PZT-PCN system with the formula (1 - x)Pb(Zr <inf>1/2</inf>Ti<inf>1/2</inf>)O<inf>3</inf>-(x)Pb(Co<inf>1/3</inf>Nb <inf>2/3</inf>)O<inf>3</inf>, where x = 0.1-0.5, were prepared using a solid-state mixed-oxide technique (the columbite-wolframite precursor method). The phase formation behavior and microstructure were studied using X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), respectively. The dielectric and ferroelectric properties of the compounds were studied and discussed. Phase-pure perovskites of PZT-PCN ceramics were obtained over a wide compositional range. In addition, the XRD, dielectric, and ferroelectric properties confirmed that the morphotropic phase boundary (MPB) composition between the tetragonal and pseudo cubic phases of this system lied between 0.2 ≤ × ≤ 0.3. © 2008 The Japan Society of Applied Physics.
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