SYNTHESIS OF CoFe2O4/Pb(Zr0.53Ti0.47)O3 MULTIFERROIC COMPOSITE THICK FILMS BY LOW-SINTERING-TEMPERATURE SCREEN PRINTING METHOD

2011 ◽  
Vol 01 (01) ◽  
pp. 119-125 ◽  
Author(s):  
W. CHEN ◽  
C. X. HUANG ◽  
T. S. YAN ◽  
W. ZHU ◽  
Z. P. LI ◽  
...  

CoFe 2 O 4/ Pb ( Zr 0.53 Ti 0.47) O 3 (abbreviated as CFO/PZT) multiferroic composite thick films were successfully fabricated on alumina substrate with gold bottom electrode by screen printing method at a low-sintering temperature. The processing included the modification and dispersion of ferromagnetic CFO powder and ferroelectric PZT powder, the preparation of uniform pastes, and the selection of proper annealing temperature for composite thick films. Transmission electron microscopic pictures (TEM) indicated the submicron meter of particles size for both CFO and PZT particles. After annealing at 900°C for 1 h in air, tape test confirmed the quality of multiferroic thick films as well as pure CFO and PZT films. X-ray diffraction (XRD) showed a coexistence of CFO and PZT phases; furthermore, a smooth surface was observed through scanning electron microscopic (SEM) pictures along with the sharp cross-sectional picture, indicative of 100 μm of film thickness. Ferromagnetic and ferroelectric properties were observed in CFO/PZT films simultaneously at room temperature. Compared with the reported CFO/PZT multiferrroic thin films, the present ferromagnetic property was closing to that of the chemical sol-gel synthesized film and even that from the physical pulsed laser deposition technique. However, the ferroelectric property showed a degenerated behavior, possible reasons for this was discussed and further optimization was also proposed for the potential multifunctional application.

2008 ◽  
Vol 15 (01n02) ◽  
pp. 41-45
Author(s):  
SUNG-GAP LEE ◽  
HYUN-JI NOH ◽  
YOUNG-HIE LEE

Ferroelectric PbZr 0.6 Ti 0.4 O 3 (PZT) thick films were fabricated using a combination of screen-printing method and PZT precursor sol coating process (M. Koch, N. Harris, R. Maas, A. G. R. Evans, N. M. White and A. Brunnschweiler, Meas. Sci. Technol.8 (1997) 49; Y. S. Yoon, J. Korean. Phys. Soc.47 (2005) 321). Structural and electrical properties of the PZT thick films with the treatment of sol coating were investigated. The porosity decreased and the densification was enhanced with increasing the number of sol coatings. All PZT thick films showed the typical X-ray diffraction patterns of a perovskite polycrystalline structure. The thickness of all thick films was approximately 60–61 μm. The relative dielectric constant increased and dielectric loss decreased with increasing the number of sol coatings, and the values of the six-layer PZT-6 film were 167.8, 0.78% at 1 kHz, respectively. The remanent polarization and coercive field of the 6-coated PZT-6 thick films were 14.1 μC/cm2 and 20.3 kV/cm, respectively.


2011 ◽  
Vol 687 ◽  
pp. 51-54
Author(s):  
Zhao Lin Huang ◽  
Bin Peng ◽  
Ke Tan ◽  
Wen Xu Zhang ◽  
Wan Li Zhang

In this paper, barium hexaferrite thick films with thickness of 80 microns were prepared on alumina substrates by screen printing method for applications in self-biased planar microwave devices. The influences of sintering temperature on the microstructures and magnetic properties of barium ferrite (BaM) thick films were investigated. The results show that with the increase of sintering temperature, the grain size increases and the porosity of the BaM thick films decreases. When the sintering temperature is below 1200 °C, the BaM thick films show magnetic properties with coercive force of about 3.5 kOe and magnetization at 20 KOe (4πM20kOe) of about 1750 Gs. When the sintering temperature is greater than 1200 °C, the magnetic properties deteriorate remarkably and exhibit a coercive force of 0.4 kOe and 4πM20kOe of about 480 Gs due to the over-sintering and diffusion of Al atoms into the BaM thick films. A new non-ferromagnetic phase Al13Ba7 is formed, which is detected by XRD.


2007 ◽  
Vol 124-126 ◽  
pp. 663-666 ◽  
Author(s):  
Sung Gap Lee ◽  
Sang Man Park ◽  
Young Jae Shim ◽  
Young Chul Rhee

PZT(70/30) powder was prepared by a sol-gel method and PZT thick films were fabricated by the screen-printing method on the alumina substrates. The coating and drying procedure was repeated 4 times. And then the PZT(30/70) precusor solution was spin-coated on the PZT thick films. A concentration of a coating solution was 0.5 mol/L and the number of coating was varied from 0 to 6. The porosity decreased and the grain size increased with increasing the number of coatings. The thickness of the PZT-6(6: number of coatings) films was about 60~65μm. All PZT thick films showed the typical XRD patterns of a typical perovskite polycrystalline structure. The relative dielectric constant of the PZT-6 thick film was 540. The remanent polarization and coercive field of the PZT-6 film were 23.6 μC /cm2, 12.0 kV/cm, respectively.


2007 ◽  
Vol 124-126 ◽  
pp. 659-662
Author(s):  
Sung Pill Nam ◽  
Sung Gap Lee ◽  
Seong Gi Bae ◽  
Young Hie Lee

The BaTiO3/SrTiO3 heterolayered thick films were fabricated by two different methods – thick films of BaTiO3 by screen printing method on alumina substrates electrodes with Pt, thin films of SrTiO3 by the spin-coating method on BaTiO3 thick films and once more thick films of BaTiO3 by the screen printing method on SrTiO3 layer. The leakage current and the dielectric properties were investigated for effect of various stacking sequence of sol-gel-prepared SrTiO3 layer at interface of BaTiO3 thick films. The insertion of SrTiO3 interlayer yielded BaTiO3 thick films with homogeneous and dense grain structure with the number of SrTiO3 layers. The leakage current density of the BaTiO3/SrTiO3-7 film is less that 1.5 10-9 A/cm2 at 5 V.


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