Inducing Layer Dependence of BiFeO3 Based Multilayer Capacitors

2009 ◽  
Vol 60-61 ◽  
pp. 256-259 ◽  
Author(s):  
Ya Feng Luo ◽  
Dan Xie ◽  
Yong Yuan Zang ◽  
Rui Song ◽  
Tian Ling Ren ◽  
...  

Multifunctional BiFeO3 (BFO) thin films were deposited on Bi3.15Nd0.85Ti3O12 (BNdT)/Pt and Pb(Zr1−x,Tix)O3 (PZT)/Pt substrates respectively by sol-gel process. The ferroelectric properties were studied for Metal-Ferroelectric-Mental (MFM) capacitors. The MFM structure exhibited well clockwise capacitance-voltage hysteresis loops due to the ferroelectric polarization of multilayer thin films achieved. The remnant polarization (2Pr) of the BFO/PZT and BFO/PZT multilayer capacitors were 45.1μC/cm2 and 23.2μC/cm2, respectively at the applied voltage of 8V. The leakage current of Pt/BFO/BNdT/Pt is about 3×10-5A/㎝2 at applied voltage of 4V, one order smaller than Pt/BFO/PZT/Pt capacitor. For the BFO/BNdT/Pt, it exhibited a weak saturated ferromagnetic response at room temperature and the multilayer was anti-ferromagnetic. However, for the BFO/PZT/Pt, well-developed M-H loops together with remnant magnetizations can be observed in at room temperature. The highest saturation magnetizations (Ms) of both capacitors were measured to be 2.47emu/cm3.

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.


2011 ◽  
Vol 197-198 ◽  
pp. 1781-1784
Author(s):  
Hua Wang ◽  
Jian Li ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.


1993 ◽  
Vol 321 ◽  
Author(s):  
Chianping Ye ◽  
Paul Baude ◽  
Dennis L. Polla

ABSTRACTThin LiTaO3 films were prepared by spin coating of polymerized sol-gel precursor solution. Films have been deposited on single crystal silicon substrate, Ti/Pt or SiO2 coated silicon substrate. Films were characterized by x-ray diffraction, dielectric and pyroelectric Measurements. High Curie temperature (above 550 °C) was assumed for LiTaO3 thin films from the temperature dependence of dielectric constant. Replacing 35% of tantalum by titanium atoms in the LiTaO3 precursor solution has resulted the thin films with Curie temperature of 330 °C. The lower Curie temperature leads to the larger pyroelectric coefficient at room-temperature, which is more than double that of the undoped LiTaO3 thin films. The dielectric, pyroelectric, and ferroelectric properties have been compared to the single crystal LiTaO3 and ceramic Li0.91Ta0.73Ti0.36O3. LiTaO3 thin films are available by sol-gel process at low temperature, and their properties may possibly be controlled by varying the composition of the sol-gel precursor solution.


2014 ◽  
Vol 703 ◽  
pp. 51-55
Author(s):  
Jia Zeng ◽  
Ming Hua Tang ◽  
Zhen Hua Tang ◽  
Yong Guang Xiao ◽  
Long Peng ◽  
...  

Bi0.94Ce0.06Fe0.97Ti0.03O3 and Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films were fabricated via sol-gel process on Pt/Ti/SiO2/Si substrates. The influence of Bi3.15Nd0.85Ti3O12 buffer layer on microstructure and electrical properties of Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films were investigated in detail. Well-saturated P-E hysteresis loops can be obtained in Bi0.94Ce0.06Fe0.97Ti0.03O3 films with Bi3.15Nd0.85Ti3O12 buffer. The remnant polarization (2Pr) of the double-layered thin films is 112 μC/cm2. The coercive field (2Ec) of double-layered films is 672 kV/cm, which is much lower than that of the Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films. The leakage current density of Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films is 4.12×10-5 A/cm2.


2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.


2010 ◽  
Vol 150-151 ◽  
pp. 112-117 ◽  
Author(s):  
Min Xian Shi ◽  
Wei Mao ◽  
Yan Qin ◽  
Zhi Xiong Huang ◽  
Dong Yun Guo

Pb(Zr0.53Ti0.47)O3 thin films with thickness of 120nm, 190nm, 310nm, 440nm and 630nm were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process through repeating spining process 2 times, 4 times, 6 times, 8 times and 10 times respectively. The structures of PZT films were investigated by SEM and XRD analysis. The ferroelectric hysteresis loops were recorded by Radiant Precision Workstation and dielectric properties were measured using an Agilent HP4294A impedance analyzer. X-ray diffraction indicated that with the film thickness increasing, the diffraction intensity increased. The thickness of PZT film had great effect on ferroelectric and dielectric properties. Conclusively when the film thickness was about 310nm, the PZT thin films possessed better ferroelectric and dielectric properties.


2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.


Sign in / Sign up

Export Citation Format

Share Document