Interface Properties Between SrTiO3 Thin Films and Electrodes

1999 ◽  
Vol 596 ◽  
Author(s):  
A. M. Clark ◽  
Jianhua Hao ◽  
Weidong Si ◽  
X. X. Xi
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Barrier Height ◽  
Electric Fields ◽  
Electrode Materials ◽  
Low Frequency ◽  
Metal Electrode ◽  
Schottky Barriers ◽  
Oxide Electrodes ◽  
Order Of Magnitude

AbstractSrTiO3 (STO) thin films were grown by pulsed laser deposition on single crystal STO substrates with a SrRuO3 buffer layer, which also serves as a bottom electrode. Measurements of the low frequency dielectric properties were performed in a parallel plate capacitor configuration for a range of temperatures using different top electrode materials. The contribution to the interfacial potential from Schottky barriers was investigated. In comparison to STO single crystals, thin films have continued dielectric non-linearity above T ∼ 70 K. This complicates conventional Schottky barrier height measurements using C-V curves because both Schottky barriers and dielectric non-linearity result in a decrease in dielectric constant under applied electric fields. However, by using I-V data, difficulties related to field dependence of the dielectric constant may be removed. Barrier height measurements for both metal and oxide electrodes were performed for T > 70 K. Calculated barrier heights from a modified Schottky equation were very low for an oxide electrode, and an order of magnitude higher for a normal metal electrode.

Effect of Bottom Electrodes on Structural and Electrical Properties of Laser Ablated SrBi2Ta2O9 Thin Films

2001 ◽  
Vol 688 ◽  
Author(s):  
Rasmi R. Das ◽  
W. Pérez ◽  
P. Bhattacharya ◽  
Ram. S. Katiyar
Keyword(s):  
Thin Films ◽  
Barrier Height ◽  
Ferroelectric Properties ◽  
High Resistivity ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Oxide Electrodes ◽  
Maximum Value ◽  
Structural And Electrical Properties ◽  
Raman Modes

AbstractWe have grown SrBi2Ta2O9 (SBT) thin films on various bottom electrodes such as Pt/TiO2/SiO2/Si (Pt) and LaNiO3/Pt/TiO2/SiO2/Si (LNO) substrates. The substrate temperature and oxygen pressure for the SBT film was maintained at 500 °C and 200 mTorr. As-grown films were post-annealed at a temperature of 800 °C. X-ray diffraction studies revealed that as-grown films were amorphous and crystallized to single phase after annealing. The difficulty of obtaining lowest Raman modes of SBT on platinized silicon substrate was overcome by using conducting oxide electrodes. Films grown on platinized silicon showed maximum value of remanent polarization (2Pr ∼ 21.5 μC/cm2) with coercive field (Ec) of ∼ 67 kV/cm. The degradation of ferroelectric properties of the films was observed with the introduction of 50 nm conducting LaNiO3 electrode at the interface of Pt and SBT film, which was attributed to high resistivity of the oxide electrode layers. Leakage current density was studied with the consideration of the Schottky emission model. The barrier height of the films grown on Pt and LNO were estimated to be 1.27 eV and 1.12 eV, respectively. The reduction of barrier height was attributed to the lower work function of the LNO electrode.

Enhancement on the Electrical Properties of PVDF/MgO Nanocomposite Thin Films

2015 ◽  
Vol 1134 ◽  
pp. 16-22
Author(s):  
Adillah Nurashikin Arshad ◽  
Rozana Mohd Dahan ◽  
Mohamad Hafiz Mohd Wahid ◽  
Muhamad Naiman Sarip ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Low Frequency ◽  
Annealed Sample ◽  
High Resistivity ◽  
Tangent Loss ◽  
Annealing Temperatures ◽  
Metal Insulator Metal ◽  
Nanocomposite Thin Films ◽  
Tan Δ

Poly (vinylideneflouride)/nanomagnesium oxide (PVDF/MgO) film with MgO loading percentage of 7% were annealed with various annealing temperatures ranging from 70°C to 170°C. The PVDF/MgO(7%) thin films were fabricated using spin coating technique with metal-insulator-metal (MIM) configuration and the dielectric constant of PVDF/MgO(7%) with respect to annealing temperatures was studied. The PVDF/MgO nanocomposite thin films annealed at temperature of 70°C (AN70) showed an improvement in the dielectric constant of 27 at 103 Hz compared to un-annealed sample (UN), which is 21 at the same frequency. As the annealing temperatures were increased from 90°C (AN90) to 150oC (AN150), the dielectric constant of PVDF/MgO(7%) were found to gradually decreased from 25 to 12 respectively, interestingly lower than the UN thin films. AN70 also produced low value of tangent loss (tan δ) at frequency of 103 Hz. The resistivity value of AN70 was also found to increase from 3.08×104Ω.cm (UN-PVDF) to 1.05×105Ω.cm. The increased in dielectric constant, with low tangent loss and high resistivity value suggests that 70°C was the favourable annealing temperature for PVDF/MgO(7%) for application in electronic devices such as low frequency capacitor.

scholarly journals Electrical and Structural Properties of PVDF/Mgo (7%) Nanocomposites Thin Films at Various Annealing Temperatures

2017 ◽  
Vol 3 (1) ◽  
pp. 8 ◽  
Author(s):  
Rozana Mohd Dahan ◽  
Arshad A.N. ◽  
Wahid M.H. ◽  
Sarip M.N. ◽  
Rusop M.
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electronic Devices ◽  
Low Frequency ◽  
Annealed Sample ◽  
High Resistivity ◽  
Tangent Loss ◽  
Annealing Temperatures ◽  
Metal Insulator Metal ◽  
Tan Δ

Abstract—Poly (vinylideneflouride)/nano-magnesium oxide (PVDF/MgO) film with 7% MgO loading percentage was annealed at various annealing temperatures ranging from 70°C to 150°C. The PVDF/MgO thin film was fabricated using spin coating technique with a metal-insulator-metal (MIM) configuration. The dielectric and electric properties of PVDF/MgO with respect to annealing temperatures was studied. The PVDF/MgO nanocomposites thin films annealed at temperature of 70°C (AN70-PVDF/MgO) showed an improvement in the properties; dielectric constant value of 26 at 1 kHz frequency compared to un-annealed sample (UN-PVDF/MgO), which is 21 at the same frequency. As the annealing temperatures were increased from 90°C (AN90) to 150°C (AN150-PVDF/MgO), the dielectric constant values were found to gradually decreased from 25 to 12 respectively, which was lower than the UN-PVDF/MgO thin films. AN70-PVDF/MgO also produced relatively low tangent loss (tan δ). The resistivity value of AN70-PVDF/MgO was also found to increase from 3.08x104 Ω.cm (UN- PVDF/MgO) to 4.55x104 Ω.cm. The increased in the dielectric constant, with low tangent loss and high resistivity value suggests that 70°C was the favorable annealing temperature for PVDF/MgO film suitable for the application in electronic devices such as low frequency capacitor.

Polarization Relaxation in KDP-Isomorph Ferroelectrics

1989 ◽  
Vol 166 ◽  
Author(s):  
Vicki Homer ◽  
Ronald Edge
Keyword(s):  
Dielectric Constant ◽  
Electric Fields ◽  
Curie Point ◽  
Bragg Peak ◽  
Low Frequency ◽  
Two Dimensional ◽  
Sensitive Detector ◽  
Capacitance Bridge ◽  
Position Sensitive ◽  
Sufficient Strength

ABSTRACTThe two-dimensional position sensitive detector at IPNS was used to probe the splitting of a single Bragg peak of the ferroelectric KD2PO4 (DKDP) at temperatures below the Curie point. The (440) peak was split into four components as the crystal itself divided into four domains. When the crystal was subjected to electric fields of sufficient strength and duration, these peaks would change in relative intensity, thus displaying the rearrangement of the domain structure as the crystal changed its level of polarization. Even at temperatures 15–20K below the Curie point, the polarized crystal was observed to relax back to an almost completely unpolarized state upon removal of the applied electric field. This indicates that the true coercive field for the crystal at this temperature was much smaller than values previously reported [l]. Low frequency dielectric constant studies using a capacitance bridge have since been conducted, which confirm and expand on these results.

Electrical and Dielectric Characteristics of SrTiO3 Thin Films Grown by PE-MOCVD Technique

1993 ◽  
Vol 335 ◽  
Author(s):  
Z. Q. Shi ◽  
C. Chern ◽  
S. Liang ◽  
Y. Lu ◽  
A. Safari
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Room Temperature ◽  
Bottom Electrode ◽  
Electrode Materials ◽  
Mocvd Technique

AbstractEpitaxial strontium titanate (SrTiO3) thin films have been grown by plasma enhanced metalorganic chemical vapor deposition (PE-MOCVD) technique on different bottom electrode materials, such as Pt/MgO and YBCO/LaAlO3. The as grown SrTiO3 film exhibited an epitaxial structure with <100> orientation perpendicular to the substrates as examined by X-ray diffraction (XRD). The electrical and dielectric properties of the films were investigated by capacitance-voltage (C-V) and current-voltage (I-V) measurements in a temperature range from 80K to 300K. The dielectric constant and dielectric loss were found to be 320 and 0.08 at 100 kHz and room temperature. The dc leakage current density and breakdown voltage were strongly dependent on the choice of the bottom electrode materials. For the films grown on YBCO/LaAlO3, the leakage current density is 8.8×10−7 A/cm2 at 200 kV/cm and the breakdown voltage is about 2.0 MV/cm. These results indicated that the SrTiO3 films are suitable for many devices applications. The frequency dependence of the dielectric constant and dielectric loss were studied in the range of 12 Hz to 1 MHz at room temperature. With the increase of the frequency, the dielectric constant showed a little decrease, while the dielectric loss exhibited a sharp increase which could be attributed to the electrode resistance loss.

Dielectric Behavior of PVDF/PP-PT Nanocomposite Thin Films

2014 ◽  
Vol 1002 ◽  
pp. 11-16
Author(s):  
Ting Ting Yu ◽  
Zhao Hui Ren ◽  
Si Min Yin ◽  
Xin Yang ◽  
Yi Feng Yu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Low Frequency ◽  
Weight Ratio ◽  
Dielectric Behavior ◽  
Β Phase ◽  
Nanocomposite Thin Films ◽  
Coating Method

PVA/PVP-assisted hydrothermal method was used to prepare single-crystal pre-perovskite PbTiO3(PP-PT) nanofibers, in which polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) acted as surfactants. Subsequently, poly (vinylidene fluoride)/ pre-perovskite PbTiO3nanofibers (PVDF/PP-PT) nanocomposite thin films were successfully fabricated by a spin-coating method. The test results showed that PP-PT nanofibers had a good distribution in PVDF matrix. Moreover, α-phase coexisted with β-phase in the PVDF and PVDF/PP-PT nanocomposite thin films. The dielectric properties of the PVDF/PP-PT nanocomposite thin films were measured as a function of frequency in the range of 5 kHz to 5 MHz. It is worth noting that the dielectric constant of nanocomposite thin films increased with increasing the weight ratio of PP-PT nanofibers in the low frequency range. By contrast, the dielectric constant of PVDF/PP-PT nanocomposite thin film which contained 20% PP-PT nanofibers was 43.7% larger than that of pure PVDF thin film (εr= 6.77) at 5 kHz, and the loss tangent was ~0.03.

Leakage Current Behavior in CaZrO3 Thin Films for High-k Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
Ting Yu ◽  
Weiguang Zhu ◽  
Xiaofeng Chen ◽  
Yuekang Lu
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Electric Fields ◽  
Current Density ◽  
Breakdown Strength ◽  
Sol Gel ◽  
High K

ABSTRACTElectrical properties and leakage current mechanisms of perovskite CaZrO3 dielectric thin films have been studied in this paper. CaZrO3 thin films were deposited on Pt/SiO2/n-Si substrate by the sol-gel wet chemical technology, and then annealed at temperatures ranging from 550 to 700 °C for 1h in O2. The films with platinum (Pt) top and bottom electrodes were characterized with respect to the leakage current as a function of temperature and applied voltage. The CaZrO3 film annealed at 600 °C was amorphous and showed good electrical properties with a dielectric constant of about 15 and leakage current density of 10−8 A/cm2 at high applied electrical field of 2.5 MV/cm. The data can be interpreted via a Schottky barrier model. The conduction mechanism at low electric fields is due to Ohmic conduction. On the other hand Schottky mechanism dominates at the intermediate fields. The high dielectric constant, low leakage current density and high breakdown strength suggest that the CaZrO3 thin film is a promising candidate for high-k applications.

The Effect of Annealing Temperatures on the Dielectric Constant of PVDF/MgO Nanocomposites Thin Films

2014 ◽  
Vol 895 ◽  
pp. 221-225 ◽  
Author(s):  
Adillah Nurashikin Arshad ◽  
Rozana Mohd Dahan ◽  
Mohamad Hafiz Mohd Wahid ◽  
Muhamad Naiman Sarip ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Magnesium Oxide ◽  
Low Frequency ◽  
Unannealed Sample ◽  
Annealing Temperatures ◽  
Β Phase ◽  
Rapid Removal

Poly(vinylidene flouride)/nano-magnesium oxide (PVDF/MgO) nanocomposites with MgO loading percentage of (7% wt. %) were annealed with various annealing temperatures ranging from 70°C to 170°C with rapid removal from the oven. From dielectric constant, the samples annealed at temperature of 70°C showed an improvement in the dielectric constant from 21 to 23 at frequency 103 Hz for UN and AN70 respectively. However, as the temperatures were increased, the dielectric constant of PVDF/MgO (7%) was found to decrease. XRD showed the presence of β-phase for PVDF/MgO(7%) sample annealed at 70°C in comparison to unannealed sample, hence PVDF/MgO(7%) film is suitable to be used for low frequency capacitor application.

Dielectric Properties of Pulsed Laser Deposited SrTiO3 Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
A. M. Clark ◽  
Jianhua Hao ◽  
Weidong Si ◽  
X. X. Xi
Keyword(s):  
Thin Films ◽  
Single Crystals ◽  
Temperature Regime ◽  
Electrode Materials ◽  
Structural Phase ◽  
Low Frequency ◽  
Pulsed Laser ◽  
Dead Layer ◽  
Low Loss ◽  
Layer Effect

AbstractLow frequency dielectric loss and nonlinearity in pulsed laser deposited SrTiO3 thin films were studied. A low loss tangent in the order of 10−4, close to the level found in SrTiO3 single crystals, was observed. Combined with a large tunability, this resulted in a figure of merit for frequency and phase agile materials that can rival that observed in single crystals. The SrTiO3 thin films with thickness ranging from 25 nm to 2.5μ1 were grown on SrRuO3 electrode layers. The loss depends strongly on the thickness, but differently above and below T ∼ 80 K. Our result suggests that, in the high temperature regime, the interfacial dead layer effect dominates while, in the low temperature regime, the losses related to the structural phase transition and quantum fluctuations are important. The effect of interfacial potential was studied by using different electrode materials that result in different Schottky barriers.

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