Ferroelectric ceramics such as BaTiO<sub>3</sub>, PbTiO<sub>3</sub> and PLZI has been widely used in piezo-and pyroelectric devices. Ferroelectric thin films can be integrated with large-scale ...Ferroelectric ceramics such as BaTiO<sub>3</sub>, PbTiO<sub>3</sub> and PLZI has been widely used in piezo-and pyroelectric devices. Ferroelectric thin films can be integrated with large-scale inte-grated circuits, so the films can be used for many kinds of microelectronic and electroopticdevices, such as NVFRAM, SAW devices, optical switches and optical展开更多
Bi3.25La0.75Ti3O12（BLT）thin films were prepared on Pt/Ti/SiO2/Si substrate by the sol-gel method.The effect of annealing on their structures and ferroelectric properties was investigated.The XRD patterns indicate th...Bi3.25La0.75Ti3O12（BLT）thin films were prepared on Pt/Ti/SiO2/Si substrate by the sol-gel method.The effect of annealing on their structures and ferroelectric properties was investigated.The XRD patterns indicate that the BLT films annealed at different temperatures are randomly orientated and the single perovskite phase is obtained at 550℃.The remmant polarization increnses and the coercive field decreases with the annealing temperature increasing.The leakage current density of the BLT films annealed at 700℃ is about 5.8×10^-8A/cm^2 at the electrie field of 250kv/cm.展开更多
Properties of ferroelectric xBiInO3-（1-x）PbTiO3（xBI-（1-x）PT） thin films deposited on（101） SrRuO3/（200）Pt/（200） MgO substrates by rf magnetron sputtering method and effects of deposition conditions are inve...Properties of ferroelectric xBiInO3-（1-x）PbTiO3（xBI-（1-x）PT） thin films deposited on（101） SrRuO3/（200）Pt/（200） MgO substrates by rf magnetron sputtering method and effects of deposition conditions are investigated.The structures of the xBI-（1-x）PT films are characterized by x-ray diffraction and scanning electron microscopy.The results indicate that the thin films are grown with mainly（001） orientation. The chemical compositions of the films are analyzed by scanning electron probe and the results indicate that the loss phenomena of Pb and Bi elements depend on the pressure and temperature during the sputtering process.The sputtering parameters including target composition, substrate temperature, and gas pressure are adjusted to obtain optimum sputtering conditions. To decrease leakage currents,2 mol% La2 O3 is doped in the targets. The P-E hysteresis loops show that the optimized xBI-（1-x）PT（x = 0.24） film has high ferroelectricities with remnant polarization2 Pr = 80μC/cm2 and coercive electric field 2 EC = 300 kV/cm. The Curie temperature is about 640℃. The results show that the films have optimum performance and will have wide applications.展开更多
Sol-gel process was adopted to prepare BiFeO3 films.BiFeO3 films were deposited on LaNiO3 coated Si（100） substrates annealed at 500 and 550 ℃,respectively.The X-ray diffraction results reveal that BiFeO3 film has a...Sol-gel process was adopted to prepare BiFeO3 films.BiFeO3 films were deposited on LaNiO3 coated Si（100） substrates annealed at 500 and 550 ℃,respectively.The X-ray diffraction results reveal that BiFeO3 film has a rhombohedrally distorted perovskite structure with space group R3c.The film annealed at 500 ℃ has larger remnant polarization（Pr） of 35.3 μC/cm2.For the film annealed at 550 ℃,smaller remnant polarization of Pr=4.8 μC/cm^2 is observed for its low breakdown electric field.Lower leakage conduction is observed in the film annealed at 500 ℃ at low applied field.展开更多
Neodymium-doped strontium bismuth titanate （SrBi4-xNdxTi4O15） ferroelectric thin films were fabricated using the sol-gel method on Pt/Ti/SiO2/Si substrates. The influence of Nd content on the microstructure and ferr...Neodymium-doped strontium bismuth titanate （SrBi4-xNdxTi4O15） ferroelectric thin films were fabricated using the sol-gel method on Pt/Ti/SiO2/Si substrates. The influence of Nd content on the microstructure and ferroelectric properties of SrBi4-xNdxTi4O15 thin films were systematically studied. The results indicated that the SrBi3.88Nd0.12Ti4O15 （SBNT0.12） thin films had better ferroelectric properties, with a remanent polarization of （2Pr） of 34.3 μC/cm^2 and a coercive field （2Ec） of 220 kV/cm. This could be attributed to the fact that SBNT0.12 ferroelectric thin films consisted of more and larger ball-like grains, approximately 150-200 nm, with structure distortion, which greatly contributed to the improvement of the ferroelectric properties of the films. Furthermore, the film exhibited a good fatigue resistant property. The value of 2Pr after 10^10 switching cycles did not change significantly. The SrBi3.88Nd0.12Ti4O15 films were promising candidates for the application of FeRAMs.展开更多
The 0.9Pb（Sc0.5Ta0.5）O3-0.1PbTiO3/0.55Pb（Sc0.5Ta0.5）O3-0.45 PbTiO3 multilayer thin films（（PSTT10/45）n, n = 1-6, 10） are deposited on SiO2/Si（100） substrates by radio frequency magnetron sputtering technique ...The 0.9Pb（Sc0.5Ta0.5）O3-0.1PbTiO3/0.55Pb（Sc0.5Ta0.5）O3-0.45 PbTiO3 multilayer thin films（（PSTT10/45）n, n = 1-6, 10） are deposited on SiO2/Si（100） substrates by radio frequency magnetron sputtering technique with La Ni O3 buffer and electrode layer, and the films are subsequently annealed by a two-step rapid thermal approach. It is found that the interfacial density of the film has an important influence on the electric property of the film. The electric property of the film increases and reaches its critical point with the increase of interface density, and then decreases with the further increase of the interface density. With an interfacial density of 16 μm-1, the film shows an optimized dielectric property（high dielectric constant, εr = 765, lowest dielectric loss, tan δ = 0.041, at 1 k Hz） and ferroelectric property（highest remnant polarization,2Pr = 36.9 μC/cm2, low coercive field, 2Ec = 71.9 k V/cm）. The possible reason for the electric behavior of the film is the competition of the interface stress with the interface defect.展开更多
BiFeO3-PbTiO3 (BFO-PT) thin films were prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD) technique under different oxygen pressures. The structures of the films were characterized by means of XRD...BiFeO3-PbTiO3 (BFO-PT) thin films were prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD) technique under different oxygen pressures. The structures of the films were characterized by means of XRD. The current densities were performed to check the conductivity of the films. The dielectric constant and loss factor (tanδ) of the films were measured. The results show that the BFO-PT layers are mainly perovskite structured; the film deposited under 6.665 Pa exhibits low leakage current, low dielectric loss (0.017-0.041) and saturated hysteresis loop with polarization (Pr) value and coercive field (Ec) of 3 μC/cm2 and 109 kV/cm.展开更多
The PZT thin films were prepared on （111）- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb（CH3COO）2], zirconium nitrate [Zr（NO3）4] were used as raw materials. The X-ray diffractometer （XRD） an...The PZT thin films were prepared on （111）- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb（CH3COO）2], zirconium nitrate [Zr（NO3）4] were used as raw materials. The X-ray diffractometer （XRD） and scanning electron microscopy （SEM） were used to characterize the phase structure and surface morphology of the films annealed at 650 ~C but with different holding time. Ferroelectric and dielectric properties of the films were measured by the ferroelectric tester and the precision impedance analyzer, respectively. The PZT thin films were constructed with epoxy resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer （DMA）. The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins-annealed film shows peak value of 0.9, hi^her than the pure epoxy resin.展开更多
（Ba0.4Pb0.3）Sr0.3TiO3 thin films were fabricated via pulsed laser deposition （PLD） technique on Pt/TiO2/SiO2/Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental r...（Ba0.4Pb0.3）Sr0.3TiO3 thin films were fabricated via pulsed laser deposition （PLD） technique on Pt/TiO2/SiO2/Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental results suggested deposition parameters, especially the deposition temperature was the key factor in forming the perovskite structure. The dielectric properties of the film deposited with optimized parameters were studied by an Agilent 4294A impedance analyzer at 1 MHz. The dielectric constant was 772, and the loss tangent was 0.006. In addition, the well-shaped hysteresis loop also showed that the film had a well performance in ferroelectric. The saturated polarization P, remnant polarization Pr and coercive field E were about 4.6 μC/cm2, 2.5 μC/cm2 and 23 kV/cm （the coercive voltage is 0.7 V）, respectively. It is suggested the film should be a promising candidate for microwave applications and nonvolatile ferroelectric random access memories （NvFeRAMs）.展开更多
The Bi3.25La0.75Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us-ing X-ray diffraction and atomic force microscopy...The Bi3.25La0.75Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us-ing X-ray diffraction and atomic force microscopy. The thin films showed a perov- skite phase and dense microstructure. The 2Pr and 2Vc of the Bi3.25La0.75Ti3O12 thin films annealed at 700℃ were 18.6 μC/cm2 and 4.1 V, respectively, under an applied voltage 10 V. After the switching of 1×1010 cycles, the Pr value decreased to 90% of its pre-fatigue values. The films showed good insulating behavior according to the test of leakage current. The dielectric constant and the dissipation factor of the Bi3.25La0.75Ti3O12 thin films were about 176 and 0.046 at 1 kHz, respectively.展开更多
We have investigated the preparation and properties of Bi3.4Ce0.6Ti3O12 thin films. The Bi3.4Ce0.6Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of...We have investigated the preparation and properties of Bi3.4Ce0.6Ti3O12 thin films. The Bi3.4Ce0.6Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us- ing X-ray diffraction and atomic force microscopy. The thin films showed a perovskite phase and dense microstructure. The dielectric constant and the dissi- pation factor of the Bi3.4Ce0.6Ti3O12 thin films were about 172 and 0.031 at 1 kHz, respectively. The 2Pr and 2Ec of the Bi3.4Ce0.6Ti3O12 thin films were 67.1 μC/cm2 and 299.7 kV/cm, respectively, under an applied field of 600 kV/cm. The Bi3.4Ce0.6Ti3O12 film did not show fatigue up to 4.46×109 switching cycles at a frequency of 1 MHz, and showed good insulating behavior according to the test of leakage current.展开更多
We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12, BHT) thin films on Pt/Ti/SiO2/Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ra...We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12, BHT) thin films on Pt/Ti/SiO2/Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The BHT film shows a single phase of Bi-layered Aurivillius structure and dense microstructure. The 2Pr and 2Ec of the 600-nm-thick BHT film were 38.4 μC/cm2 and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the BHT film shows good in-sulating behavior according to the test of leakage current.展开更多
The （Bi0.9Ho0.1）3.999Ti2.997V0.003012 （BHTV） films have been prepared on Pt/Ti/SiO2/Si substrates by solgel method. The microstructure and ferroelectric properties of the BHTV films were investigated. The BHTV fil...The （Bi0.9Ho0.1）3.999Ti2.997V0.003012 （BHTV） films have been prepared on Pt/Ti/SiO2/Si substrates by solgel method. The microstructure and ferroelectric properties of the BHTV films were investigated. The BHTV films show a single phase of Bi-layered Aurivillius structure and dense microstructure. The Ho3＋/V5＋ cosubstitution can effectively improve the ferroelectric properties. The BHTV film exhibits good ferroelectric properties with 2Pr of 47.6℃/cm2, 2Ec of 265 kV/cm （at applied field of 420 kV/cm）, dielectric constant of 305, dielectric loss of 0.031 （at 1 MHz）, good insulting behavior, as well as the fatigue-free behavior.展开更多
The Bi4Zr0.5Ti2.5O12 (BZT) thin films were fabricated on the LaNiO3 bottom electrode using sol-gel method. The structure and morphology of the films were character-ized using X-ray diffraction, AFM and SEM. The result...The Bi4Zr0.5Ti2.5O12 (BZT) thin films were fabricated on the LaNiO3 bottom electrode using sol-gel method. The structure and morphology of the films were character-ized using X-ray diffraction, AFM and SEM. The results show that the films have a perovskite phase and dense microstructure. The 2Pr and 2Vc of the Pt/BZT/LaNiO3 capacitor are 28.2 μC/cm2 and 14.7 V respectively at an applied voltage of 25 V. After the switching of 1×1010 cycles, the Pr value decreases to 87% of its pre-fatigue val-ues. The dielectric constant (ε) and the dissipation factor (tanδ) of the BZT thin films are about 204 and 0.029 at 1 kHz, respectively. The films show good insulating behavior according to the test of leakage current. The clockwise C-V hysteresis curve observed shows that the Pt/BZT/LaNiO3 structure has a memory effect be-cause of the BZT film’s ferroelectric polarization.展开更多
基金Project supported by the National Natural Science Foundation of Chinapartially by the Electronic Material Research Laboratory of Xi'an Jiaotong University.
文摘Ferroelectric ceramics such as BaTiO<sub>3</sub>, PbTiO<sub>3</sub> and PLZI has been widely used in piezo-and pyroelectric devices. Ferroelectric thin films can be integrated with large-scale inte-grated circuits, so the films can be used for many kinds of microelectronic and electroopticdevices, such as NVFRAM, SAW devices, optical switches and optical
文摘Bi3.25La0.75Ti3O12（BLT）thin films were prepared on Pt/Ti/SiO2/Si substrate by the sol-gel method.The effect of annealing on their structures and ferroelectric properties was investigated.The XRD patterns indicate that the BLT films annealed at different temperatures are randomly orientated and the single perovskite phase is obtained at 550℃.The remmant polarization increnses and the coercive field decreases with the annealing temperature increasing.The leakage current density of the BLT films annealed at 700℃ is about 5.8×10^-8A/cm^2 at the electrie field of 250kv/cm.
基金Supported by the National Natural Science Foundation of China under Grant No 11304160the Special Fund for Public Interest of China under Grant No 201510068,and the NUPTFC under Grant No NY215111
文摘Properties of ferroelectric xBiInO3-（1-x）PbTiO3（xBI-（1-x）PT） thin films deposited on（101） SrRuO3/（200）Pt/（200） MgO substrates by rf magnetron sputtering method and effects of deposition conditions are investigated.The structures of the xBI-（1-x）PT films are characterized by x-ray diffraction and scanning electron microscopy.The results indicate that the thin films are grown with mainly（001） orientation. The chemical compositions of the films are analyzed by scanning electron probe and the results indicate that the loss phenomena of Pb and Bi elements depend on the pressure and temperature during the sputtering process.The sputtering parameters including target composition, substrate temperature, and gas pressure are adjusted to obtain optimum sputtering conditions. To decrease leakage currents,2 mol% La2 O3 is doped in the targets. The P-E hysteresis loops show that the optimized xBI-（1-x）PT（x = 0.24） film has high ferroelectricities with remnant polarization2 Pr = 80μC/cm2 and coercive electric field 2 EC = 300 kV/cm. The Curie temperature is about 640℃. The results show that the films have optimum performance and will have wide applications.
基金Funded by the National Natural Science Foundation of China(No.10874075)the Key Program of Hubei Province Education Committee(No. D20082203)
文摘Sol-gel process was adopted to prepare BiFeO3 films.BiFeO3 films were deposited on LaNiO3 coated Si（100） substrates annealed at 500 and 550 ℃,respectively.The X-ray diffraction results reveal that BiFeO3 film has a rhombohedrally distorted perovskite structure with space group R3c.The film annealed at 500 ℃ has larger remnant polarization（Pr） of 35.3 μC/cm2.For the film annealed at 550 ℃,smaller remnant polarization of Pr=4.8 μC/cm^2 is observed for its low breakdown electric field.Lower leakage conduction is observed in the film annealed at 500 ℃ at low applied field.
基金the National Natural Science Foundation of China (60471042)the Natural Science Foundation of Shandong Province (Y2007F36)
文摘Neodymium-doped strontium bismuth titanate （SrBi4-xNdxTi4O15） ferroelectric thin films were fabricated using the sol-gel method on Pt/Ti/SiO2/Si substrates. The influence of Nd content on the microstructure and ferroelectric properties of SrBi4-xNdxTi4O15 thin films were systematically studied. The results indicated that the SrBi3.88Nd0.12Ti4O15 （SBNT0.12） thin films had better ferroelectric properties, with a remanent polarization of （2Pr） of 34.3 μC/cm^2 and a coercive field （2Ec） of 220 kV/cm. This could be attributed to the fact that SBNT0.12 ferroelectric thin films consisted of more and larger ball-like grains, approximately 150-200 nm, with structure distortion, which greatly contributed to the improvement of the ferroelectric properties of the films. Furthermore, the film exhibited a good fatigue resistant property. The value of 2Pr after 10^10 switching cycles did not change significantly. The SrBi3.88Nd0.12Ti4O15 films were promising candidates for the application of FeRAMs.
基金Project supported by the National Natural Science Foundation of China(Grant No.60771016)the Scientific Research Foundation of Mianyang Normal University,China(Grant No.QD2013A07)
文摘The 0.9Pb（Sc0.5Ta0.5）O3-0.1PbTiO3/0.55Pb（Sc0.5Ta0.5）O3-0.45 PbTiO3 multilayer thin films（（PSTT10/45）n, n = 1-6, 10） are deposited on SiO2/Si（100） substrates by radio frequency magnetron sputtering technique with La Ni O3 buffer and electrode layer, and the films are subsequently annealed by a two-step rapid thermal approach. It is found that the interfacial density of the film has an important influence on the electric property of the film. The electric property of the film increases and reaches its critical point with the increase of interface density, and then decreases with the further increase of the interface density. With an interfacial density of 16 μm-1, the film shows an optimized dielectric property（high dielectric constant, εr = 765, lowest dielectric loss, tan δ = 0.041, at 1 k Hz） and ferroelectric property（highest remnant polarization,2Pr = 36.9 μC/cm2, low coercive field, 2Ec = 71.9 k V/cm）. The possible reason for the electric behavior of the film is the competition of the interface stress with the interface defect.
基金Project(04A1B18) supported by Shanghai Municipal Education Commission Project(50472098) supported by the National Natural Science Foundation of China Project(04qmx1440) supported by Shanghai Rising Star Program, China
文摘BiFeO3-PbTiO3 (BFO-PT) thin films were prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD) technique under different oxygen pressures. The structures of the films were characterized by means of XRD. The current densities were performed to check the conductivity of the films. The dielectric constant and loss factor (tanδ) of the films were measured. The results show that the BFO-PT layers are mainly perovskite structured; the film deposited under 6.665 Pa exhibits low leakage current, low dielectric loss (0.017-0.041) and saturated hysteresis loop with polarization (Pr) value and coercive field (Ec) of 3 μC/cm2 and 109 kV/cm.
基金Supported by the National Natural Science Foundation of China (No. 50772083)China-Japan Cooperation Program(No. 2010DFA51270)the Fundamental Research Funds for the Central Universities
文摘The PZT thin films were prepared on （111）- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb（CH3COO）2], zirconium nitrate [Zr（NO3）4] were used as raw materials. The X-ray diffractometer （XRD） and scanning electron microscopy （SEM） were used to characterize the phase structure and surface morphology of the films annealed at 650 ~C but with different holding time. Ferroelectric and dielectric properties of the films were measured by the ferroelectric tester and the precision impedance analyzer, respectively. The PZT thin films were constructed with epoxy resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer （DMA）. The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins-annealed film shows peak value of 0.9, hi^her than the pure epoxy resin.
基金the National Natural Science Foundation of China(No.60571009)
文摘（Ba0.4Pb0.3）Sr0.3TiO3 thin films were fabricated via pulsed laser deposition （PLD） technique on Pt/TiO2/SiO2/Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental results suggested deposition parameters, especially the deposition temperature was the key factor in forming the perovskite structure. The dielectric properties of the film deposited with optimized parameters were studied by an Agilent 4294A impedance analyzer at 1 MHz. The dielectric constant was 772, and the loss tangent was 0.006. In addition, the well-shaped hysteresis loop also showed that the film had a well performance in ferroelectric. The saturated polarization P, remnant polarization Pr and coercive field E were about 4.6 μC/cm2, 2.5 μC/cm2 and 23 kV/cm （the coercive voltage is 0.7 V）, respectively. It is suggested the film should be a promising candidate for microwave applications and nonvolatile ferroelectric random access memories （NvFeRAMs）.
基金the Natural Science Foundation of Hubei Province (Grant Nos. 2003ABA061, 2004ABA082)
文摘The Bi3.25La0.75Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us-ing X-ray diffraction and atomic force microscopy. The thin films showed a perov- skite phase and dense microstructure. The 2Pr and 2Vc of the Bi3.25La0.75Ti3O12 thin films annealed at 700℃ were 18.6 μC/cm2 and 4.1 V, respectively, under an applied voltage 10 V. After the switching of 1×1010 cycles, the Pr value decreased to 90% of its pre-fatigue values. The films showed good insulating behavior according to the test of leakage current. The dielectric constant and the dissipation factor of the Bi3.25La0.75Ti3O12 thin films were about 176 and 0.046 at 1 kHz, respectively.
基金the Natural Science Foundation of Hubei Province (Grants No. 2004ABA082)
文摘We have investigated the preparation and properties of Bi3.4Ce0.6Ti3O12 thin films. The Bi3.4Ce0.6Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us- ing X-ray diffraction and atomic force microscopy. The thin films showed a perovskite phase and dense microstructure. The dielectric constant and the dissi- pation factor of the Bi3.4Ce0.6Ti3O12 thin films were about 172 and 0.031 at 1 kHz, respectively. The 2Pr and 2Ec of the Bi3.4Ce0.6Ti3O12 thin films were 67.1 μC/cm2 and 299.7 kV/cm, respectively, under an applied field of 600 kV/cm. The Bi3.4Ce0.6Ti3O12 film did not show fatigue up to 4.46×109 switching cycles at a frequency of 1 MHz, and showed good insulating behavior according to the test of leakage current.
基金the Hubei Province Natural Science Foundation (Grant No. 2007ABA309)
文摘We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12, BHT) thin films on Pt/Ti/SiO2/Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The BHT film shows a single phase of Bi-layered Aurivillius structure and dense microstructure. The 2Pr and 2Ec of the 600-nm-thick BHT film were 38.4 μC/cm2 and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the BHT film shows good in-sulating behavior according to the test of leakage current.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China under grant No.50902108
文摘The （Bi0.9Ho0.1）3.999Ti2.997V0.003012 （BHTV） films have been prepared on Pt/Ti/SiO2/Si substrates by solgel method. The microstructure and ferroelectric properties of the BHTV films were investigated. The BHTV films show a single phase of Bi-layered Aurivillius structure and dense microstructure. The Ho3＋/V5＋ cosubstitution can effectively improve the ferroelectric properties. The BHTV film exhibits good ferroelectric properties with 2Pr of 47.6℃/cm2, 2Ec of 265 kV/cm （at applied field of 420 kV/cm）, dielectric constant of 305, dielectric loss of 0.031 （at 1 MHz）, good insulting behavior, as well as the fatigue-free behavior.
基金Supported by Natural Science Foundation of Hubei Province (Grant No. 2004ABA082)
文摘The Bi4Zr0.5Ti2.5O12 (BZT) thin films were fabricated on the LaNiO3 bottom electrode using sol-gel method. The structure and morphology of the films were character-ized using X-ray diffraction, AFM and SEM. The results show that the films have a perovskite phase and dense microstructure. The 2Pr and 2Vc of the Pt/BZT/LaNiO3 capacitor are 28.2 μC/cm2 and 14.7 V respectively at an applied voltage of 25 V. After the switching of 1×1010 cycles, the Pr value decreases to 87% of its pre-fatigue val-ues. The dielectric constant (ε) and the dissipation factor (tanδ) of the BZT thin films are about 204 and 0.029 at 1 kHz, respectively. The films show good insulating behavior according to the test of leakage current. The clockwise C-V hysteresis curve observed shows that the Pt/BZT/LaNiO3 structure has a memory effect be-cause of the BZT film’s ferroelectric polarization.
