Bottom Electrodes for High Dielectric Oxide Compounds: Effects on Crystallization of Lead Containing Ferroelectrics

1993 ◽  
Vol 310 ◽  
Author(s):  
A. Grill ◽  
D. Beach ◽  
C. Smart ◽  
W. Kane
Keyword(s):  
Crystallization Behavior ◽  
Single Phase ◽  
Electrode Materials ◽  
Sol Gel ◽  
Dielectric Materials ◽  
Crystallographic Structure ◽  
X Ray ◽  
Integrated Devices ◽  
High Dielectric Materials ◽  
High Dielectric

AbstractSeveral conductive structures, which appeared to be usable as base electrodes for integrated devices based on high dielectric materials, have been annealed for 30 minutes in oxygen at 650 °C. Similar structures coated with lead-based ferroelectrics deposited by the sol-gel method have been annealed for 1 min in oxygen at higher temperatures. The materials have been characterized by Rutherford backscattering (RBS) and scanning electron microscopy (SEM) and the crystallographic structure of the ferroelectrics films has been determined by X-ray diffractometry (XRD).Only RuO2/Ru has been found to be suitable as an electrode, at temperatures not exceeding 650 °C. It has also been found that the electrode materials can strongly affect the crystallization behavior of the sol-gel ferroelectric films and the formation of single-phase perovskite layers.

Electrode Structures for Integration of Ferroelectric or High Dielectric Constant Films in Semiconductor Devices

1998 ◽  
Vol 541 ◽  
Author(s):  
Alfred Grill
Keyword(s):  
Electrode Materials ◽  
High Dielectric Constant ◽  
Semiconductor Devices ◽  
Dielectric Materials ◽  
Ferroelectric Thin Films ◽  
Perovskite Materials ◽  
Perovskite Material ◽  
High Dielectric Materials ◽  
High Dielectric ◽  
Processing Steps

AbstractThe preparation of ferroelectric and high-dielectric perovskite materials, which is performed at high temperatures in oxidizing environments, imposes strong limitations on the choice of suitable electrode materials which can be used for integration of these materials with semiconductor devices. Because of the complex compositions of the perovskites and of some of the electrode materials the two can interact and result in the deterioration of the structures. The electrode materials have, therefore, to be used often in combination with suitable barriers which block diffusion of the elements of the perovskite and of the Si device and prevent interactions between the components. These requirements can result in complex, multilayered electrode/barrier structures that can affect the crystallization of the perovskite material and its electrical properties as well as the perovskite properties during subsequent processing steps (e.g. in forming gas anneals). The present paper will review the different electrode/barrier structures that have been proposed for integration of ferroelectric thin films with semiconductor devices and discuss their effects on the properties of ferroelectric and high-dielectric materials.

scholarly journals The Study of Magnetic Properties for Non-Magnetic Ions Doped BiFeO3

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4061
Author(s):  
Yongtao Li ◽  
Liqing Liu ◽  
Dehao Wang ◽  
Hongguang Zhang ◽  
Xuemin He ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Local Structure ◽  
Metal Ion ◽  
Single Phase ◽  
Sol Gel ◽  
X Ray ◽  
Co Doping ◽  
Magnetic Ions ◽  
X Ray Absorption ◽  
Fe Ions

BiFeO3 is considered as a single phase multiferroic. However, its magnetism is very weak. We study the magnetic properties of BiFeO3 by Cu and (Cu, Zn). Polycrystalline samples Bi(Fe0.95Cu0.05)O3 and BiFe0.95(Zn0.025Cu0.025)O3 are prepared by the sol-gel method. The magnetic properties of BiFe0.95(Zn0.025Cu0.025)O3 are greater than that of BiFeO3 and Bi(Fe0.95Cu0.05)O3. The analyses of X-ray absorption fine structure data show that the doped Cu atoms well occupy the sites of the Fe atoms. X-ray absorption near edge spectra data confirm that the valence state of Fe ions does not change. Cu and Zn metal ion co-doping has no impact on the local structure of the Fe and Bi atoms. The modification of magnetism by doping Zn can be understood by the view of the occupation site of non-magnetically active Zn2+.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

Study on optical and magnetic properties of FexNi1-xMn2O4 materials

2021 ◽  
Vol 66 (1) ◽  
pp. 57-64
Author(s):  
Hang Pham Vu Bich ◽  
Yen Nguyen Hai ◽  
Mai Phung Thi Thanh ◽  
Dung Dang Duc ◽  
Hung Nguyen Manh ◽  
...  
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
Raman Scattering Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Spectrum ◽  
Diffraction Diagram ◽  
Optical And Magnetic Properties ◽  
Scanning Electron

In this study, we present the process of synthesis FexNi1-xMn2O4 (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9; 1) by method sol-gel. Scanning electron microscope results shows that the particle size is about 50 nm. The X-ray diffraction diagram shows that the samples are single phase, changing structure clearly as the x ratio increases from 0 to 1. The lattice constant, the bond length also changes with x-value as shown on the Raman scattering spectrum. The results of the vibrating sample magnetometer show that the magnetism of the material FexNi1-xMn2O4 changes with the value of x and reaches a maximum in the range x from 0.5 to 0.7.

Synthesis of Polymer-based ZnO/TiO2 Nanocomposites Flexible Sheets as High Dielectric Materials

2021 ◽  
Vol 63 (6) ◽  
pp. 879-890
Author(s):  
N. Kanwal ◽  
S. Pervaiz ◽  
A. Rasheed ◽  
M. Saleem ◽  
I. A. Khan
Keyword(s):  
Dielectric Materials ◽  
High Dielectric Materials ◽  
High Dielectric

Electrochemical Performance of La0.7Sr0.3Cu1-xFexO3-δ as Cathode Material in IT-SOFCs

2010 ◽  
Vol 160-162 ◽  
pp. 666-670
Author(s):  
Min Zhang Zheng ◽  
Xiao Mei Liu
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Cathode Material ◽  
Single Phase ◽  
Cathodic Polarization ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cathodic Overpotential ◽  
A Current

To obtain more detail information about the cathode of La0.7Sr0.3Cu1-xFexO3-δ（x= 0.1,0.3,0.5,0.7,0.9）in IT-SOFCs, the cathode material La0.7Sr0.3Cu1-xFexO3-δ（x=0.1, 0.3, 0.5, 0.7, 0.9）was synthesized by a sol-gel method. X-ray diffraction revealed it to be form a single phase of perovskite. The high temperature electrical conductivity was measured by using the four-point dc technique, and cathodic overpotential with SDC（Sm0.15Ce0.85O1.925） electrolyte support was measured by using a current-interruption technique. The investigation of electrocheimical properties suggested that La0.7Sr0.3Cu0.7Fe0.3O3-δ has the highest electrical conductivity and the lowest cathodic polarization. Using La0.7Sr0.3Cu0.7Fe0.3O3-δ as cathode and 65%NiO/SDC as anode based on SDC electrolyte one can obtain higher current density and power density at intermediate temperatures, La0.7Sr0.3Cu0.7Fe0.3O3-δ is considered to be a possible cathode adapted to IT-SOFCs.

Advances in Precursor Development for CVD of Bariumcontaining Materials

1993 ◽  
Vol 335 ◽  
Author(s):  
Brian A. Vaartstra ◽  
R. A. Gardiner ◽  
D. C. Gordon ◽  
R. L. Ostrander ◽  
A. L. Rheingold
Keyword(s):  
State Of The Art ◽  
Chemical Vapor ◽  
Dielectric Materials ◽  
Barium Strontium ◽  
Barium Compounds ◽  
Recent Developments ◽  
Metal Organic ◽  
High Dielectric Materials ◽  
High Dielectric ◽  
Memory Applications

AbstractBarium titanate and barium-strontium titanate (BST) are high dielectric materials, likely to replace state-of-the-art capacitor materials for memory applications. Chemical Vapor Deposition (CVD) of these materials has been hampered, particularly by the lack of suitable precursors for barium. Although attempts to make volatile metal-organic barium compounds have met with some progress, a suitably stable, volatile barium source is still in demand. This paper will highlight recent developments at ATM, including syntheses and structures of polyamine and glycol ether adducts which have been designed to limit aggregation of barium diketonates, and stabilize the adducts with respect to ligand dissociation.

FABRICATION AND CHARACTERIZATION OF AQUEOUS SOL–GEL-DERIVED LaFeO3 THIN FILMS

2000 ◽  
Vol 14 (22n23) ◽  
pp. 801-808 ◽  
Author(s):  
M. RAJENDRAN ◽  
M. GHANASHYAM KRISHNA ◽  
A. K. BHATTACHARYA
Keyword(s):  
Thin Films ◽  
Single Phase ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Average Particle Size ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Correlation Spectroscopy ◽  
Average Particle ◽  
X Ray

A novel all-inorganic aqueous sol–gel process has been developed to fabricate LaFeO3 thin films by dip-coating. Stable, positively charged colloidal sol particles of hydrous lanthanum ferrite with an average particle size (Z av ) of 7 nm were prepared and coated onto quartz plates under controlled conditions. The sols have been characterized using photon correlation spectroscopy (PCS) for Z av and size distribution. The redispersible gel was characterized by thermogravimetric and differential thermal analysis (TG-DTA) and also by isothermal heating followed by X-ray diffraction to identify the reaction sequence to form LaFeO 3. The sol–gel films as deposited were X-ray amorphous on heating up to 500°C, partially crystalline at 600°C, fully crystalline and single phase at 650°C and above. These films were continuous, polycrystalline, single phase, had uniform thickness in the range between 180 to 1000 nm, depending on deposition conditions, and showed about 80% optical transmittance. The optical band gap varied from 2.7 to 3.3 eV as a function of the annealing temperature. The refractive index increased with increase in annealing temperature from 1.55 at 500°C to 1.86 at 800°C.

Effects of Calcination Temperature on the Phase Formation and Microstructure of Barium Zinc Tantalate

2010 ◽  
Vol 173 ◽  
pp. 61-66 ◽  
Author(s):  
Hidayani Jaafar ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain
Keyword(s):  
Phase Formation ◽  
Raw Materials ◽  
Dielectric Materials ◽  
Particle Sizes ◽  
Complex Perovskite ◽  
Pure Phase ◽  
Microwave Electronic ◽  
High Dielectric Materials ◽  
High Dielectric ◽  
Quality Factor Q

Nowadays, high dielectric materials are important materials in microwave electronic applications due to its properties that can provide high frequency range of an antenna. Barium Zinc Tantalate (BZT) is a complex perovskite structure that can produce high quality factor, Q. In this research, the effect of calcinations temperatures on phase formation, density and morphology of BZT powders were investigated. Based on the DTA result, the range of calcinations temperatures to be investigated were between 750°C to 1250°C. Results show that the maximum density of BZT occurred at 1150°C with 99.74% theoretical density. Samples calcined at below 1100°C still containing their raw materials such as BaCO3, ZnO and Ta2O5. The pure phase of BZT was formed at 1150°C when calcined for 1 hour. The lattice distortion of BZT increased when the calcinations temperature increased between 1000°C to 1150°C. The calcined powders show almost spherical morphology and agglomerated. The particle sizes of BZT increased from 0.716μm to 0.258μm when the temperature increased from 750°C to 1200°C.

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