Phase formation and electrical properties of (Ba0.4Sr0.4Ca0.2)(Zr0.05Ti0.95)O3 ceramics perpared by seed induced method

Name: Jiraporn Dangsak

Organization : Mae Fah Luang University

keyword: Ceramics

LCSH: Ceramics

Classification :.LCCS: TP807

LCSH: Ceramic materials

LCSH: Dielectrics

LCSH: Materials -- Electric properties

Abstract: In this research, the fabrication and characterization of Lead-free (Ba0.4Sr0.4Ca0.2)(Zr0.05Ti0.95)O3 (BSCZT) ceramics were prepared by the seed induced method. The methodology is divided into two parts. First, prepared BaTiO3, CaTiO3, Ba0.6Sr0.4TiO3 (BST) and BaZr0.05TiO0.95 (BZT) nano crystal seed by molten salt method. The phase formation of seed powder was examined by X-ray diffraction and morphology characterized by scanning electron microscope (SEM). Results showed that all the samples have pure perovskite phase and all nano crystal seeds have cubic shape. Secondly, prepared the BSCZT ceramic using ball-milling and added BaTiO3, CaTiO3, BST and BZT seed powder. Each seed powders with a concentration of 0, 2.5, 5, 7.5, 10 mol% were then mixed with BSCZT starting powder for 24 hours, After that, mixture powder was calcined at 1250 ºC for 2 hours. After calcined process the BSCZT powder pressed into pellets and sintered at 1400 °C for 4 hours. Phase formations of the calcined powders and sintered samples were determined by X-ray diffraction (XRD) technique. The density of sintered pellets was determined according to Archimedes’ principle. The morphology was examined by a scanning electron microscope (SEM). The dielectric constant (εr) and dielectric loss (tanδ) was measured as a function of frequency and temperature using an automated electrical measurement system. The results were divided into three parts. In the first part, (Ba0.4Sr0.4Ca0.2)(Zr0.05Ti0.95O3) ceramics used BST seed at 2.5, 5, 7.5 and 10 mol% were produced by seed-induced method. The all ceramic samples showed pure perovskite phase and confirm tetragonal phase. Maximum density value of 6.94 ± 0.07 μm was achieved when concentration up to 7.5 mol% and the average grain size slightly decreased with seed concentration more than 7.5 mol%. The best electrical properties in (Ba0.4Sr0.4Ca0.2)(Zr0.1Ti0.9O3) systems were found at seed = 7.5 mol% with the highest dielectric constant, (r) 8111 (1 kHz at Tc) and dielectric loss of 0.0113. In the second part, Ba0.4Sr0.4Ca0.2Zr0.05Ti0.95O3 ceramics using BST-BZT seed prepared by the seed induced method. All samples show pure perovskite phase structure without secondary phase. The density value decreased from 4.90 to 4.75 g/cm3 and the average grain size sample increased from 3.71 to 8.99 µm. The highest value of r  8707 was found in the sample with seed at 10 mol%. In the final part, a system which BT, CT and BZT-seed were added to (Ba0.4Sr0.4Ca0.2)(Zr0.1Ti0.9O3) ceramics. For BSCZT ceramics after sintering at 1400 °C pure perovskite phase structures were shown in all samples with no impurity. The grain size of the sample without BT, CT and BZT-seed was 3.71 ± 0.05 µm, whereas the grain size of 6.36 ± 0.80 µm was observed in the sample with 2.5 mol%. The sample with a seed concentration higher than 2.5 mol% grain sizes tend to decrease. The High dielectric constant is ~ 9142 and dielectric loss of 0.0065 can observe in the sample with 2.5 mol% BT, CT and BZT-seed. The dielectric constant was found to be increased as the grain size increase.

Mae Fah Luang University

Address: CHIANG RAI

Email: library@mfu.ac.th

Name: ๊Uraiwan Intatha

Role: Advisor

Name: Nattaya Tawichai

Role: Co-Advisor

Created: 2017

Issued: 2561

Modified: 2018-10-05

Issued: 2018-10-05

วิทยานิพนธ์/Thesis

application/pdf

CallNumber: Thesis TP807 J618p 2017

eng

DegreeName: Master of Science

Level: Master's Degree

Descipline: Materials Science

Grantor: Mae Fah Luang University

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	Jiraporn Dangsak.pdf	7.25 MB	2	2025-09-12 16:29:32

ใช้เวลา

0.025728 วินาที