MINISTRY OF EDUCATION AND
TRAINING
VIET NAM ACADEMY OF SCIENCE
AND TECHNOLOGY
GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY
……………..*****…………….
NGUYEN VAN KHIEN
Fabrications of ferroelectric materials do not contain Pb on
BaTiO3 substrate and study their electricity and piezoelectricity
properties
Specialized: Electronic materials
Numerical code: 62.44.01.23
SUMMARY OF DOCTORAL IN MATERIALS
SCIENCE
Ha noi, 2018
The work is completed at:
INSTITUTE OF MATERIALS SCIENCE - VIET NAM ACADEMY OF
SCIENCE AND TECHNOLOGY
Science supervisor:
1. PGS.TS Le Van Hong
2. PGS. TS. Nguyen Van Dang
PhD dissertation reviewer 1:
PhD dissertation reviewer 2:
PhD dissertation reviewer 3:
The thesis will be protected under supervisory board academy level at:
Academy at ….. hours….. day …..month ….. 2018
People can find this thesis at:
- National library
- Graduate university of Science and Technology library
LIST OF PROJECTS PUBLISHED
Articles in the ISI directory
1. Le Van Hong, Nguyen Van Khien and Truong Van Chuong,
“Dielectric Relaxation of Ba1¹xCaxTiO3 (x = 0.00.3)”, Materials
Transactions, Vol. 56, No. 9 (2015) pp. 1374 to 1377.
2. Van Khien Nguyen, Thi Hong Phong Le, Thi Kim Chi Tran, Van
Chuong Truong and Van Hong Le, “Influence of Ca Substitution
on Piezoelectric Properties of Ba1xCaxTiO3” Journal of electronic
materials, DOI: 10.1007/s11664-017-5332-0 (2017).
3. Nguyen Van Khien, Than Trong Huy, Le VanHong, “AC
conduction of Ba1-xCaxTiO3 and BZT-BCTx”, Physica B,
S0921-4526(17)30193-X (2017).
Articles published in domestic magazines
4. Nguyễn Văn Khiển, Vũ Đình Lãm và Lê Văn Hồng, “Ba1-
xCaxTiO3 và tính chất điện môi của chúng”, Tạp chí Khoa học và
Công nghệ 52(3C) (2014) 725-730
5. Nguyen Van Khien, Vu Dinh Lam and Le Van Hong, “Ba1-
xCaxTiO3 AND THE DIELECTRIC PROPERTIES”,
Communications in Physics, Vol. 24, No. 2 (2014), pp. 170-176.
6. Nguyễn Văn Khiển, Trương Văn Chương, Đặng Anh Tuấn, và Lê
Văn Hồng, “Ảnh hưởng sự thay thế Ca cho Ba lên tính sắt điện
của hệ Ba1-xCaxTiO3”, Hội nghị Vật lý chất rắn và Khoa học vật
liệu toàn quốc lần thứ 9 - SPMS2015
7. Nguyen Van Khien and Le Van Hong, “ Effect of Ca concentration
substituting for Ba on structure and ferroelectric properties of BZT-
BCT material”, Vietnam Journal of Science and Technology 56 (1A)
(2018) 86-92
Related articles.
8. T. D. Thanh, P. T. Phong, D. H. Mạnh, N. V. Khien, L. V. Hong,
T. L. Phan, S. C. Yu, Low-field magnetoresistance in
La0.7Sr0.3MnO3/BaTiO3 composites, J mater SCI (2013) 24: 1389-
1394.
9. Nguyễn Văn Khiển, Trịnh Phi Hiệp, Nguyễn Thị Dung và Nguyễn
Văn Đăng, Nghiên cứu ảnh hưởng của biên pha nano BaTiO3 lên
tính chất điện từ của vật liệu La0.7Sr0.3MnO3, Tạp chí Khoa học và
Công nghệ Đại học Thái Nguyên, tập 118 số 4, 2014, trang 197-
202
Introduction
Piezoelectric materials is a material that can can generate a Voltage
corresponding to mechanical stess change. Although it was discovered in
1880, it was not widely used until the 1950s. Over the past half decade,
PZT ceramics materials (PbZr1-xTixO3) have been studied and
demostrated by researchers and It has a relatively large piezoelectric
coefficient (d33 = 220 ÷ 590 pC / N). That‟s why most piezoelectric
applications, both telephone batteries and high-tech scanning-tunneling
microscopes use PZT piezoelectric materials.However, Pb is a radioactive
element. It not only is very dangerous to humans but also it is one of the
causes of global environmental pollution if used extensively. Therefore, it
is imperative for scientists to find out that piezoelectric materials not
contain Pb with a high piezoelectric coefficient which can be use instead of
traditional PZT materials. Some piezoelectric materials not contain Pb
have recently been publish and have shown good results. Special, material
systems not contain Pb on (K,Na)NbO3 and BaTiO3 substated.
However, in our understanding, piezoelectric material systems not contain
Pb have not been adequately researched. There are some publications
published in international journals, but a few and sporadically. The
physical mechanism to explain the cause of the high piezoelectric
coefficient and the properties of the material is still a lot of unsoud, need to
focus more research, deeper.
In the country, piezoelectric material systems are studied by many
scientists in centers, scientific institutes and universities such as Ha Noi
unviersity of Science and Technology, University of Science-Hue
University .... In order to promote the research activities on the family of
piezoelectric materials not contain Pb and based on the actual situation as
well as research conditions such as experimental equipment, references,
research collaboration capabilities with domestic research team ... We think
that studying and solving the problems mentioned above is useful and will
give many positive results. Especially finding the relationship between the
big piezoelectric coefficient and the dielectric recovery time of the object
piezoelectric. This is why we choose this thesis “Fabrication of
ferroelectric materials do not contain Pb on BaTiO3 substrate and study
their electricity and piezoelectricity properties”. we believe that our work
will be sussces and will be useful for the understand about the interaction
electric mechanism in the ferroelectric material systems, piezoelectric not
contain Pb, also open application capacibility of these material systems in
fabrication of pin, senso… contributory on the environment reduction.
The main contents of my thesis is present in 4 chapters:
Chapter 1. Theoritical overview
Chapter 2. Experiment
Chapter 3. Effected of Ca substitution for Ba on the structure and
magnetic properties of BCT and BZT-BCT
Chapter 4.The relationship between time of restore dielectric and
piezoelectric properties of BCT and BZT-BCT
The goads of this thesis:
Successfully fabricated ceramic piezoelectric samples (Ba1-xCax)
TiO3 (BCT) and BZT-BCT by solid phase synthesis method. BZT-
BCT materials must be good quality, high piezoelectric coefficient
(500-600 pC / N).
Studying the relationship between morphological competition and
dielectric ferroelectric properties, especially with the high
piezoelectric properties of materials.
In addition, based on the results of the synchronized studies about the
material phase structure, the electric polarization of the material
depends on temperature, electric field and frequency which will
provide the analysis and general discussion contribute. Demonstrate
the physical mechanism of the phenomenon of high piezoelectri
coefficient in ferroelectric material systems.
Research object of my thesis
Research object: Piezoelectric materials.
Area of research: Piezoelectric materials do not contain Pb on
BaTiO3 substrate
Research methods: The ceramic bulk is fabricated by
solid phase reaction. Structure of materials, morphological phase,
particle size, The morphologic form of the material was investigated
and analyzed on the basis of X-ray diffraction pattern, Raman spectra
and Scanning Electron Microscope SEM. After obtaining the
necessary information on the phase structure, phase material
cleanliness, morphology and supporting information as mentioned
above we perform electrical measurements such as resistant R (T),
capacity C (T), D (E). Measurement of C (T) will be made under the
effect of high electric field to evaluate the maximum polarization of
the material. In addition, C (f) frequency-dependent measurements of
polarization are also performed to evaluate the dielectric recovery
characteristics and to indirectly evaluate the piezoelectric coefficient
of the material. Colecting all the results of the study will help us to
evaluate the dielectric polarization mechanism in the material, the
correlation between the morphological phase and the piezoelectricity