Direct observations of changes in ferroelectric domain configurations around the indentation and ahead of the crack front in soft-doped PZT

Materialia ◽  
2021 ◽  
Vol 19 ◽  
pp. 101191
Author(s):  
V.S. Kathavate ◽  
H. Sonagara ◽  
B. Praveen Kumar ◽  
I. Singh ◽  
K. Eswar Prasad
2021 ◽  
Author(s):  
V.S. Kathavate ◽  
H. Sonagara ◽  
B. Praveen Kumar ◽  
I. Singh ◽  
Korimilli Eswar Prasad

Author(s):  
J. F. DeNatale ◽  
D. G. Howitt

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.


Author(s):  
L.E. Murr

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.


Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson

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.


Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).


Author(s):  
L.E. Murr

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.


Author(s):  
Xiao Zhang

Electron holography has recently been available to modern electron microscopy labs with the development of field emission electron microscopes. The unique advantage of recording both amplitude and phase of the object wave makes electron holography a effective tool to study electron optical phase objects. The visibility of the phase shifts of the object wave makes it possible to directly image the distributions of an electric or a magnetic field at high resolution. This work presents preliminary results of first high resolution imaging of ferroelectric domain walls by electron holography in BaTiO3 and quantitative measurements of electrostatic field distribution across domain walls.


Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.


Author(s):  
E.K. Goo ◽  
R.K. Mishra

Ferroelectric domains are twins that are formed when PZT undergoes a phase transformation from a non-ferroelectric cubic phase to a ferroelectric tetragonal phase upon cooling below ∼375°C.,1 The tetragonal phase is spontaneously polarized in the direction of c-axis, making each twin a ferroelectric domain. Thin foils of polycrystalline Pb (Zr.52Ti.48)03 were made by ion milling and observed in the Philips EM301 with a double tilt stage.


Author(s):  
Nurul Nadjmi

Kepulauan Riau merupakan provinsi yang terdiri dari beberapa pulau diantaranya Pulau Batam, Pulau Bintan dan Pulau Karimun. Modal sosial merupakan serangkaian nilai dan norma informal yang dimiliki oleh kelompok masyarat dalam membagun kerjasamanya. Lingkup penelitian pada pembahasan ini adalah terfokus pada pengaruh modal sosial terhadap perkembangan pariwisata di Kepulauan Riau dalam hal ini Pulau Batam, Pulau Bintan, dan Pulau Karimun. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian deskriptif kualitatif. Penelitian ini dikondisikan sebagai penelitian kualitatif melalui strategi studi kasus. Sistem pendekatan yang digunakan juga merupakan pendekatan deskriptif analitik. Melakukan pengamatan langsung, mengumpulkan data-data kemudian menghubungkannya dengan kajian teori yang digunakan. Lokus penelitian ini terdapat di Kepulauan Riau dengan melihat pengaruh modal sosial pada perkembangan pariwisata di ketiga pulau yaitu Pulau Batam, Pulau Bintan dan Pulau Karimun. Berdasarkan hasil survey yang saya lakukan di Kepulauan Riau, terutama pada ketiga pulau yaitu Pulau Batam, Pulau Bintan, dan Pulau Karimun, dari ketiga pulau tersebut ternyata pada Pulau Karimun perkembangan pariwisatanya tidak terlalu berkembang karena masyarakat yang tidak menerima adanya wisatawan terutama wisatawan mancanegara. Riau Islands is a province consisting of several islands including Batam Island, Bintan Island and Karimun Island. Social capital is a set of informal values ​​and norms that are owned by community groups in building cooperation. The scope of research in this discussion is focused on the influence of social capital on the development of tourism in the Riau Islands, in this case Batam Island, Bintan Island, and Karimun Island. The research method used in this research is descriptive qualitative research. This research is conditioned as qualitative research through a case study strategy. The system approach used is also a descriptive analytic approach. Make direct observations, collect data and then relate it to the study of the theories used. The locus of this research is in the Riau Islands by looking at the influence of social capital on the development of tourism in the three islands, namely Batam Island, Bintan Island and Karimun Island. Based on the results of a survey I conducted in the Riau Islands, especially on the three islands, namely Batam Island, Bintan Island, and Karimun Island, of the three islands, it turns out that on Karimun Island the development of tourism is not very developed because people do not accept tourists, especially foreign tourists.


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