共查询到19条相似文献,搜索用时 78 毫秒
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报道了铁酸铋薄膜样品在80K~300K温度范围直流电学输运性质的研究结果.利用同一前驱体不同老化时间,用化学溶液沉积法在钛酸锶衬底上制备出两种样品.在低阻样品中,低场下电流随电压变化遵从欧姆定律,电阻不随温度变化;而在中等强度外场下显示出肖特基二极管性质.在高阻样品中,低场下电流密度沿晶界分布,输运中的势垒能级为0.57eV;高场下电流的传输则遵从Frenkel-Poole模型,相关势垒能级0.12eV.低阻和高阻两种样品在85K温度下可测最大剩余极化分别为2.6μC/cm2和28.8μC/cm2. 相似文献
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利用反应磁控溅射法沉积了ZrO2介电薄膜,研究了退火温度对ZrO2介电薄膜电学性能的影响,并对漏电流最小的样品的漏电流机制进行了分析。结果表明,随着退火温度的升高,漏电流先减小后增大,退火温度为300℃时所制备薄膜的漏电流最小,当所加电压为–1.4 V时,漏电流密度为8.32×10–4 A/cm2。当所加正偏压为0-0.8 V和0.8-4.0 V时,该样品的漏电流主导机制分别为肖特基发射和直接隧穿电流;当所加负偏压为–1.7-0 V和–4.0-–1.7 V时,其主导机制分别为肖特基发射和空间电荷限制电流。 相似文献
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该文采用溶胶-凝胶法在LaNiO_3/Pt/Ti/SiO_2/Si基片上制备了掺杂La元素的Pb_(1-0.05)La_(0.05)ZrTiO_3(PLZT)、掺杂Sr元素的Pb_(1-0.05)Sr_(0.05)ZrTiO_3(PSZT)、掺杂La和Sr元素的Pb_(1-0.1)La_(0.05)Sr_(0.05)ZrTiO_3(PLSZT)及未掺杂的锆钛酸铅(PZT)薄膜样品。对不同掺杂情况的样品分别进行了压电系数、电滞回线、介电特性的测试。结果表明,双掺杂样品PLSZT薄膜具有比其他样品更好的铁电性能,其剩余极化强度(P_r)为13.2μC/cm~2,饱和极化强度(P_s)为28.4μC/cm~2,矫顽场(E_c)为54.8 kV/cm;双掺杂样品PLSZT薄膜的压电系数(d_(33))比其他3种样品高,达到153 pC/N。掺杂后的样品与未掺杂的样品相比,其介电常数有略微提高;单掺杂La的样品的介电特性在高频环境下更稳定。 相似文献
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采用溶胶 凝胶方法制备出纯立方钙钛矿相、介电性能和漏电流特性良好的 (Ba0 .5Sr0 .5)TiO3 铁电薄膜 .研究发现 ,随着烧结温度的升高 ,(Ba0 .5Sr0 .5)TiO3 薄膜纯度和结晶度增高 ,介电常数提高 ,漏电流密度降低 .在 75 0℃进行保温 1h热处理的薄膜性能较好且稳定 :在室温下测得薄膜介电常数为 2 5 0 ,介电损耗为 0 .0 30 ,漏电流密度为 6 .9× 10 -8A/cm2 .较高的介电常数、较低的漏电流密度可能源于良好的纯度和结晶度 .进一步研究表明 ,薄膜导电遵从空间电荷限制电流机制 . 相似文献
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The 2-2 type BiFeO3-CuFe2O4(BFO-CFO) bilayer thin films were deposited on FTO/glass substrates by sol-gel method, using Bi(NO3)3·5H2O, Fe(NO3)3·9H2O and Cu(NO3)3·3H2O as the raw materials. The structure, surface morphologies and electric properties of the thin films were investigated. The XRD patterns show that the structure of BFO is the distorted rhombohedral perovskite with R3c:H (161) space lattice, CFO is the tetragonal spinel with type I41/amd (141) space lattice. The interface is obvious between the CFO and BFO films, which shows that the BFO and CFO have no inter-diffusion phenomena. When the frequency is 10 kHz, the dielectric loss peak is consistent with the dielectric relaxation of Wagner Maxwell. The leakage current density of BFO-CFO under positive and negative bias voltages is asymmetric, and there is a hysteresis phenomenon in the positive bias voltage. The results of XPS show that the Fe2+ of the BFO-CFO is decreased and the leakage current of the film is improved. The saturation magnetization (Ms) of BFO-CFO is 25.8 emu/cm3 at room temperature, which is about 40 times of the pure BFO. 相似文献
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采用sol-gel(溶胶-凝胶)法在Pt/Ti/SiO2/Si基底上分别制备了厚度为400nm,600nm,800nm的PZT(锆钛酸铅,Zr/Ti=52/48)薄膜,研究了厚度对薄膜介电性能与铁电性能的影响。通过对薄膜的铁电性能与介电性能进行测试,分析了不同厚度薄膜的剩余极化强度、介电常数与介电损耗;通过对介电调谐率与最大正切损耗的计算,进一步分析了薄膜的介电调谐性能。实验结果表明,薄膜的介电常数与介电损耗随薄膜厚度的增大而增加;厚度为600nm的薄膜具有最好的介电调谐性能与铁电性能。 相似文献
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利用磁控溅射法在硅(Si)衬底上沉积了Ta2O5薄膜,对薄膜进行了不同温度的退火处理,并利用X射线衍射仪对薄膜的微观结构进行了分析.然后在Si的背面和介电薄膜的上面沉积Pt电极,组成了金属—氧化物—半导体( MOS)电容器,对不同温度下退火得到的薄膜制备的MOS电容器的电学性能进行了研究.结果表明,薄膜在700℃开始结... 相似文献
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采用固相法,研究了Nd2O3掺杂量对ZBS玻璃添加的Ba0.65Sr0.35TiO3(BST)基低温烧结的陶瓷的物相组成、显微结构及介电性能的影响。结果表明:Nd2O3的掺杂并没有改变低温烧结的BST基陶瓷的物相结构,仍为单一钙钛矿结构。随着Nd2O3掺杂量的增大,BST基陶瓷的介电常数先增大然后减小,介质损耗先减小然后增大。当Nd2O3添加质量分数为1.5%,烧结温度为975℃时,BST基陶瓷的综合性能较好,此时相对介电常数为667,介质损耗为0.01,在–30~+85℃容温变化率为–35.2%~14.8%。 相似文献
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In the present work, transparent and conductive Nd doped SnO2 thin films were deposited via spray pyrolysis. Crystallographic, morphological, optical and electrical characterizations of SnO2 were researched as a function of Nd doping. The XRD analysis indicated the films had tetragonal cassiterite tin oxide structure and (211) preferential direction for NdTO-0, NdTO-1, NdTO-2 and NdTO-3 samples changed to (110) plane for NdTO-4 and NdTO-5 samples. The crystalline size and strain analysis were made by using a Williamson–Hall method. The SEM micrographs showed that all films had homogenously scattered pyramidal and small densely nanoparticles. The optical analysis indicated optical band gap value of undoped film increased with 1 at% Nd doping and then it decreased with more Nd content. The Hall measurements indicated that the highest electrical conductivity was obtained for 2 at% Nd doping content. 相似文献
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Ba6−3xNd8+2xTi18O54 with x=0.25 (BNT-0.25, or simply, BNT) dielectric thin films with a thickness of 320 nm have been prepared on Pt-coated silicon
substrates by pulsed laser deposition (PLD) at the substrate temperature of 650°C in 20 Pa oxygen ambient. X-ray analysis
showed that the as-deposited films are amorphous and the films remain amorphous after a postannealing at 750°C for 30 min.
The dielectric constant of the BNT films has been determined to be about 80 with a low loss tan δ of about 0.006 at 1 MHz.
The capacitance-voltage (C-V), capacitance-frequency, and capacitance-temperature characteristics of a BNT capacitor with
Pt top electrode were measured. A low leakage-current density of 4×10−6 A/cm2 at 6 V was measured, and a preliminary discussion of the leakage-current mechanism is also given. It is proposed that amorphous
BNT-0.25 thin films will be a potential dielectric material for microwave applications. 相似文献
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Sonet Kumar Sah M. Azizar Rahman M. R. H. Sarkar M. Shahjahan M. K. R. Khan 《半导体学报》2015,36(3):033004-6
Nanocrystalline Zn1-x CoxO(where x varies from 0 to 0.04 in steps of 0.01) thin films were deposited onto glass substrate by the spray pyrolysis technique at a substrate temperature of 350 ℃. The X-ray diffraction patterns confirm the formation of hexagonal wurtzite structure. The crystal grain size of these films was found to be in the range of 11–36 nm. The scanning electron micrographs show a highly crystalline nanostructure with different morphologies including rope-like morphology for undoped ZnO and nanowalls and semispherical morphology for Co-doped Zn O. The transmittance increases with increasing Co doping. The optical absorption edge is observed in the transmittance spectra from 530 to 692 nm, which is due to the Co2C absorption bands corresponding to intraionic d–d shifts. The direct and indirect optical band gap energies decrease from 3.05 to 2.75 eV and 3.18 to 3.00 eV, respectively for 4 mol% Co doping. The electrical conductivity increases with increasing both the Co doping and temperature, indicating the semiconducting nature of these films. The temperature dependence thermal electromotive force measurement indicates that both undoped and Co-doped ZnO thin films show p-type semiconducting behavior near room temperature. This behavior dies out beyond 313 K and they become n-type semiconductors. 相似文献
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采用磁控溅射法分别制备了不同组分的Mn-Co-Ni-O(MCNO)薄膜材料。通过对材料结构分析,发现在Mn离子数目不变的情况下,随着Co离子的增加,晶粒尺寸逐渐增大,且晶格常数先增大后减小;在Co离子数目不变的情况下,随着Mn离子的增加,薄膜的择优生长晶面由(311)不晶面向(400)晶面转变。对电学性能测试进行分析,可知薄膜材料既有Mn离子的导电机制,也有Co离子的导电机制;Mn1.2Co1.5Ni0.3O4具有最低的电阻率(235 Ω.cm),具有最高的室温负温度电阻系数︱a295︱(4.7%.K-1)值。 相似文献