Investigation of ferroelectrics using conventional and in situ electron microscopy

1994 ◽  
Vol 52 ◽  
pp. 586-587
Author(s):  
V. Saikumar ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Nonvolatile Memory ◽  
Ferroelectric Materials ◽  
Gate Insulator ◽  
Sensors And Actuators ◽  
In Situ Electron Microscopy ◽  
Ferroelectric Domains ◽  
Domain Boundaries ◽  
Domain Interactions ◽  
Memory Applications

In recent years, there has been a growing interest in the application of ferroelectric thin films for nonvolatile memory applications and as a gate insulator in DRAM structures. In addition, bulk ferroelectric materials are also widely used as components in electronic circuits and find numerous applications in sensors and actuators. To a large extent, the performance of ferroelectric materials are governed by the ferroelectric domains (with dimensions in the micron to sub-micron range) and the switching of domains in the presence of an applied field. Conventional TEM studies of ferroelectric domains structures, in conjunction with in-situ studies of the domain interactions can aid in explaining the behavior of ferroelectric materials, while providing some answers to the mechanisms and processes that influence the performance of ferroelectric materials. A few examples from bulk and thin film ferroelectric materials studied using the TEM are discussed below.Figure 1 shows micrographs of ferroelectric domains obtained from undoped and Fe-doped BaTiO3 single crystals. The domain boundaries have been identified as 90° domains with the boundaries parallel to <011>.

In-situ observations of the behaviors of ferroelectric domains in BaTiO3 under applied electric fields with TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 348-349
Author(s):  
Feng Tsai ◽  
Victoria Khiznichenko ◽  
J. M. Cowley
Keyword(s):  
Optical Microscopy ◽  
Electric Fields ◽  
Ferroelectric Materials ◽  
In Situ Tem ◽  
Bulk Crystals ◽  
Large Bulk ◽  
Ferroelectric Domains ◽  
In Situ Observations ◽  
New Interpretation

The previous studies on the behaviors of ferroelectric domains under applied electric fields were made by a number of researchers, e.g. Merz and Little on bulk BaTiO3 crystals with optical microscopy. It was suggested that under the applied electric field the new antiparallel domains nucleated and grew and 90° and 180° domains nucleated and grew sidewise. However, those results and conclusions were obtained from the experiments on large bulk crystals with optical microscopy of relatively lower magnification and resolution. TEM is a very powerful tool in the study of crystal structure and defects and may provide a new interpretation to the study of microdomains of hundred angstroms in thin ferroelectric films with a higher magnification and resolution and may be combined with electron diffraction. However, no reference has been found that an in-situ TEM study of the behaviors of ferroelectric materials under applied electric fields has ever been made.

In situ electron microscopy of ferroelectric domains

MRS Bulletin ◽  
2015 ◽  
Vol 40 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Linze Li ◽  
Jacob R. Jokisaari ◽  
Xiaoqing Pan
Keyword(s):  
Electron Microscopy ◽  
In Situ Electron Microscopy ◽  
Ferroelectric Domains ◽  
Image Position

Abstract

Observation of ferroelectric domain boundaries in PZT(52/48) with TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 370-371
Author(s):  
Feng Tsai ◽  
J. M. Cowley
Keyword(s):  
Strain Field ◽  
Lattice Distortion ◽  
Ferroelectric Domain ◽  
Ferroelectric Materials ◽  
Memory Devices ◽  
Current Interest ◽  
Ferroelectric Domains ◽  
Domain Boundaries

Lead zirconium titanates(PZT) are ferroelectric materials of considerable current interest because their potential for applications in memory devices and electrooptics has drawn the attention of industry. The performance of the devices made of PZT largely depends on the behaviors of ferroelectric domains and domain boundaries. TEM has been proved to be a very powerful tool in the study of ferroelectric domains and domain boundaries in ferroelectric materials. It is suggested that around the domain boundaries in BaTiO3 there is a distribution of lattice distortion and strain field. However, few references have been found on the study of ferroelectric domains and domain boundaries in PZT materials by TEM.

Domain Dynamics in Ferroelectric Thin Films Via In-SituTEM Analysis

1997 ◽  
Vol 3 (S2) ◽  
pp. 587-588
Author(s):  
Xiwei Lin ◽  
V.P. Dravid ◽  
O. Auciello ◽  
C. Bjormander ◽  
C.M. Foster
Keyword(s):  
Thin Films ◽  
Domain Switching ◽  
Silver Layer ◽  
Barrier Formation ◽  
Domain Boundaries ◽  
Statics And Dynamics ◽  
Memory Applications ◽  
Domain Dynamics ◽  
Charged Defects

Due to spatial constraints and small dimensions (<1 μm), the ferroelectric domain statics and dynamics in thin films can be significantly different from their bulk counterparts. Further, it has been recognized that electrode-film interfaces play a key role in the fatigue and retention phenomena in the thinfilms for ferroelectric memory applications, which are closely associated with barrier formation and charged defects trapped at various interfaces including the domain boundaries. Thus, it is imperative to utilize in-situ TEM to directly observe the domain switching at a length-scale which is essential (i.e. 1-10nm) for better understanding of the domain dynamics and their interactions with microstructure in thin filmferroelectrics.We have successfully carried out in-situ TEM observations of domain dynamics in Pb(Zr.5Ti.5)O3 (PZT) thin films using PZT-based capacitor structures. The capacitors were produced by growing PZT layers (∼550 nm thick) on SrRuO3 bottom electrode layers (∼100 nm thick) on (001) SrTiO3 substrates using MOCVD. The top electrode consisted of an ∼200 nm silver layer.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

scholarly journals Fabrication of a liquid cell for in situ transmission electron microscopy

Microscopy ◽  
2020 ◽  
Author(s):  
Xiaoguang Li ◽  
Kazutaka Mitsuishi ◽  
Masaki Takeguchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cost Effective ◽  
Production Method ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
In Situ Electron Microscopy ◽  
Liquid Cell ◽  
Si Wafer

Abstract Liquid cell transmission electron microscopy (LCTEM) enables imaging of dynamic processes in liquid with high spatial and temporal resolution. The widely used liquid cell (LC) consists of two stacking microchips with a thin wet sample sandwiched between them. The vertically overlapped electron-transparent membrane windows on the microchips provide passage for the electron beam. However, microchips with imprecise dimensions usually cause poor alignment of the windows and difficulty in acquiring high-quality images. In this study, we developed a new and efficient microchip fabrication process for LCTEM with a large viewing area (180 µm × 40 µm) and evaluated the resultant LC. The new positioning reference marks on the surface of the Si wafer dramatically improve the precision of dicing the wafer, making it possible to accurately align the windows on two stacking microchips. The precise alignment led to a liquid thickness of 125.6 nm close to the edge of the viewing area. The performance of our LC was demonstrated by in situ transmission electron microscopy imaging of the dynamic motions of 2-nm Pt particles. This versatile and cost-effective microchip production method can be used to fabricate other types of microchips for in situ electron microscopy.

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