scholarly journals Dielectric properties characterization of La- and Dy-doped BiFeO3 thin films

2007 ◽  
Vol 22 (8) ◽  
pp. 2179-2184 ◽  
Author(s):  
Peter Kr. Petrov ◽  
Vaijayanti R. Palkar ◽  
Alexander K Tagantsev ◽  
Hsin-I Chien ◽  
K. Prashanthi ◽  
...  

The dielectric response of La- and Dy- doped BiFeO3 thin films at microwave frequencies (up to 12 GHz) has been monitored as a function of frequency, direct current (dc) electric field, and magnetic field in a temperature range from 25 to 300 °C. Both the real and imaginary parts of the response have been found to be non-monotonic (oscillating) functions of measuring frequency. These oscillations are not particularly sensitive to a dc electric field; however, they are substantially dampened by a magnetic field. The same effect has been observed when the volume of the characterized sample is increased. This phenomenon is attributed to the presence of a limited number of structural features with a resonance type response. The exact origin of these features is unknown at present. Leakage current investigations were performed on the whole set of films. The films were highly resistive with low leakage current, thereby giving us confidence in the microwave measurements. These typically revealed ‘N’-type I-V characteristics.

2006 ◽  
Vol 933 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara

AbstractMn-substituted BiFeO3 (BFO) thin films were formed by chemical solutions deposition on Pt/Ti/SiO2/Si(100) structures. Effects of the Mn-substitution on the structure and ferroelectricity of BFO films were examined. We found that the lattice structure of the film is sensitive to the Mn-substitution and the secondary phase is appears in 50% Mn-substituted BFO films. The leakage current were increased with the Mn-substitution. However, the 5% Mn-substituted BFO film shows low leakage current than undoped BFO films in a high electric field than 0.5 MV/cm. Due to the low leakage current in Mn-doped 3, 5 and 7% BFO films, the saturated P-E hysteresis loops with remanent polarization around 100 μC/cm2 were obtained at RT.


1990 ◽  
Vol 203 ◽  
Author(s):  
P. Li ◽  
B. Gittleman ◽  
T.-M. Lu

ABSTRACTHigh dielectric constant thin films for packaging applications were studied. Compared with polycrystalline or epitaxial ferroelectric thin films amorphous ferroelectric films are a promising alternative because of their ease of processing and low leakage current. Reactive Partially Ionized Beam deposition (RPIB) offers a new approach to deposit high dielectric constant films at a low substrate temperature. As an example, the growth of amorphous BaTiOs thin films using RPIB deposition is described. The films were characterized in terms of dielectric constant and leakage current. The annealing effects on the film properties are also discussed.


2013 ◽  
Vol 750-752 ◽  
pp. 931-935
Author(s):  
Xue Na Yang ◽  
Jian An Liu ◽  
Bai Biao Huang ◽  
Si Jiang Gao

La-doped (Bi1-xLax)2Ti2O7 (BLTO) thin films with different La contents have been grown by CSD method. All the XRD patterns of the samples showed that the films were polycrystalline films. The intensities of the peaks decreased with the increasing of La contents. The general trend of the changes of leakage current was decreased with the increasing of x. The case of dielectric constant as a function of La content is complicated. The rule of change of the dielectric constant is different with different la contents. In view of dielectric constant and dielectric loss, we think that the film of x=0.2 has relative low leakage current and high dielectric constant, which is considered to be adequate for a DRAM.


2006 ◽  
Vol 966 ◽  
Author(s):  
Peter Kr. Petrov ◽  
Vaijayanti R Palkar ◽  
Neil McN Alford ◽  
Alexander K Tagantsev ◽  
K Prashanthi ◽  
...  

ABSTRACTThe dielectric response of La- and Dy- doped BiFeO3 thin films to electric- and magnetic fields was measured at microwave frequencies (up to 12GHz) in a temperature range from 25 °C to 300 °C. Interesting phenomena were observed. Significant oscillations in the C(f) characteristic which were unaffected by the electric field or by elevated temperature but which were dampened by a magnetic field. We also observed ‘N’-type I-V characteristics. A possible explanation for this mesoscopic response is the presence of structural features that cause resonance (e.g. grains, grain-boundaries, domains, domain walls etc), with a contribution strong enough to be averaged by the system. The exact origin of these features is unknown at present.


1993 ◽  
Vol 318 ◽  
Author(s):  
L. H. Chang ◽  
Q. X. Jia ◽  
W. A. Anderson

ABSTRACTRF magnetron sputtering of BaTiO3 on (100) p-Si was performed to produce a high-quality BaTiO3/p-Si interface and BaTi03 insulator gates with high dielectric constant and low leakage current. Through different processing and device designs, different capacitor structures, including single layer amorphous, single layer polycrystalline and bi-layer amorphous on polycrystal-line, were investigated in this study. Raman spectroscopy showed the optical phonon modes of the BaTiO3 thin films with different structures. The structural properties of the films were characterized by X-ray diffraction. Using both the quasistatic and the high-frequency capacitance-voltage measurements, the interface-trap density was estimated at high 1011 eV−1 cm−2. The relative dielectric constant of the composite structure was controlled in a range from 30 to 130. The leakage current density was as low as 8×10−10 A/cm2 at a field intensity of (2±0.5)×105 V/cm. Breakdown voltage varied from 5x105 to 2×106 V/cm.


2001 ◽  
Vol 16 (10) ◽  
pp. 3005-3008 ◽  
Author(s):  
F. Ayguavives ◽  
B. Agius ◽  
B. EaKim ◽  
I. Vickridge

Lead zirconate titanate (PZT) thin films were deposited in a reactive argon/oxygen gas mixture by radio-frequency-magnetron sputtering. The use of a metallic target allows us to control the oxygen incorporation in the PZT thin film and also, using oxygen 18 as a tracer, to study the oxygen diffusion in the thin films. Electrical properties and crystallization were optimized with a 90-nm PZT thin film grown on RuO2 electrodes. These PZT films, annealed with a very modest thermal budget (550 °C) show very low leakage current densities (J = 2 × 10−8 A/cm2 at 1 V). In this article we show that a strong correlation exists between the oxygen composition in the PZT film and the leakage current density.


Author(s):  
Alfredo Blázquez Martínez ◽  
Nicolas Godard ◽  
Naveen Aruchamy ◽  
Cosme Milesi-Brault ◽  
Oana Condurache ◽  
...  

1992 ◽  
Vol 284 ◽  
Author(s):  
T. Makita ◽  
T. Horikawa ◽  
H. Kuroki ◽  
M. Kataoka ◽  
J. Tanimura ◽  
...  

ABSTRACTThin films of (BaxSrj-x)TiO3 (BST) deposited by RF sputtering have been studied for the application to the capacitor material of dynamic random access memory (DRAM). The effects of film structures on the dielectric constant and the leakage current were investigated. The films deposited at 550–600°C consist of granular grains, and the films deposited above 650°C contain columnar grains. The dielectric constant is related to the grain size in the direction of thickness. The leakage current increases as the film structure changes from granular to columnar. The low leakage current (less than 10−8 A/cm2 at +2 and -2 V) and the small value of equivalent SiO2 thickness (0.9 nm) were attained in the (Ba065Sr035) TiO3 thin films.


2014 ◽  
Vol 602-603 ◽  
pp. 804-807
Author(s):  
Zhen Kun Xie ◽  
Zhen Xing Yue

High Curie-temperature (Tc) polycrystalline 0.2Bi (Ni1/2Ti1/2)O3-0.8PbTiO3 (0.2BNT-0.8PT) thin films were fabricated on Pt (111)/Ti/SiO2/Si substrates via an aqueous chemical solution deposition (CSD) technique. The thin films exhibited good crystalline quality and dense, uniform microstructures with an average grain size of 55 nm. The dielectric, piezoelectric and ferroelectric properties of the films was investigated. The permittivity peak appeared at 485 °C, which was 100 °C higher than that of Pb (Zr,Ti)O3 thin films. The local effective piezoelectric coefficient d33 was 45 pm/V at 3V. Moreover, a large remnant polarization with 2Pr up to 92 uC/cm2 and a small leakage current of 2.2×10-5 A/cm2 under an electric field of 400 kV/cm were obtained. The magnitude of the measured polarization and the high Curie temperature make the 0.2BNT-0.8PT films promising candidates for application in high-temperature ferroelectric and piezoelectric devices.


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