KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 10

Some of the metrics are blocked by your
consent settings
Piezoelectric composite films for real-time foot strike detection and energy generation
(2025-12-16)
Panpho, Phakakorn
;
Charoonsuk, Thitirat
;
Vittayakorn, Naratip
;
Charoenthai, Nipaphat
;
Bongkarn, Theerachai
Energy harvesting technology integrated into running shoes enables the conversion of mechanical energy from foot strikes into electrical signals for real-time monitoring. This approach enhances running efficiency, reduces injury risk, and eliminates the need for external power sources. In this study, composite films combining lead-free piezoelectric ceramics (KNNS-BNZ-xBF) with PDMS were developed for efficient energy harvesting and accurate detection of foot-strike patterns. XRD analysis revealed a broad R–O–T phase coexistence zone (0 ≤ x ≤ 0.006) and a transition to an R–T phase boundary for x > 0.006, with reduced grain size as xBF increased. The sample with xBF = 0.006 mol.% showed optimal electrical properties and was selected for composite film fabrication. Electrical output increased with ceramic loading, reaching maximum open-circuit voltage (V<inf>OC</inf>) and short-circuit current (I<inf>SC</inf>) at 18 wt% KBB due to enhanced piezoelectric response and uniform particle dispersion. The films, mounted on running shoe soles, successfully detected different foot-strike patterns (heel strike, midfoot, and forefoot). This system demonstrates strong potential for wearable sensors in athletic monitoring and injury prevention.
Some of the metrics are blocked by your
consent settings
EFFECT OF (AlNb)4+ B-SITES SUBSTITUTION ON THE PHASE STRUCTURE, MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF Bi0.47Na0.47Ba0.06TiO3 CERAMICS
(2025-01-01)
Luangpangai, Anupong
;
Chongsatan, Wistsarut
;
Charoenthai, Nipaphat
;
Chootin, Suphornphun
;
Vittayakorn, Naratip
Bi0.47Na0.47Ba0.06Ti1-x(Al0.5Nb0.5)xO3 (abbreviated as BNBT1-xANx) lead-free ceramics (x=0-0.05) were synthesized by the solid-state combustion technique. The effect of (AlNb)4+ content on the phase structure, microstructure and electrical properties was investigated. A pure perovskite structure was obtained from all specimens. Rietveld refinement revealed coexisting rhombohedral and tetragonal phases in all samples and the tetragonal phase increased with increased AlNb content (x). The morphology of the BNBT1-xANx ceramics displayed nearly round grains and anisotropic grain growth. Average grain size decreased from 1.8 to 0.7 µm when x increased from 0 to 0.05 and the grain size distribution became narrower. The density, maximum dielectric constant and remnant polarization rapidly decreased with increased x. The deterioration of the electrical properties induced by (AlNb)4+ substitution was due to shifting away from the morphotropic phase boundary (MPB), poor microstructure and low density.
Some of the metrics are blocked by your
consent settings
PHASE FORMATION, MICROSTRUCTURE AND ELECTRIC PROPERTIES OF La3+ SUBSTITUTION IN B-SITE OF LEAD-FREE BaTi0.91Sn0.09O3 CERAMICS
(2025-01-01)
Pattanakasem, Wiwat
;
Charoenthai, Nipaphat
;
Vittayakorn, Naratip
;
Thongyong, Nateeporn
;
Thongbai, Prasit
The study explored the influence of La3+ substitution at the B-site in BaTi0.91Sn0.09O3 (BTS) ceramics on their phase structure, microstructure, and electrical characteristics. La3+-doped BTS ceramics, denoted as Ba(Ti0.91Sn0.09)1-xLaxO3 (BTSL) with x = 0, 0.005, 0.010, 0.015, and 0.020, were synthesized via the conventional solid-state reaction method. The calcination and sintering processes were carried out at 1200°C for 2 hours and 1400–1450 °C for 4 hours, respectively. Results indicated that the undoped BTSL sample (x = 0) exhibited a pure perovskite phase without detectable impurities. However, when x ranged from 0.005 to 0.020, secondary impurity phases were observed alongside the perovskite structure. Phase analysis revealed that BTSL ceramics consisted of orthorhombic (O) and tetragonal (T) phases for x = 0–0.005, transitioned to a presence of O, T, and cubic (C) phases at x = 0.010–0.015, and exhibited only the C phase at x = 0.020. Rietveld refinement confirmed that La3+ occupied both A- and B-sites for compositions with x ≥ 0.005. As La3+ concentration increased, the average grain size and remnant polarization initially showed a slight reduction (x = 0 to 0.005) before significantly decreasing (x = 0.010 to 0.015). The Curie temperature (TC) was 43°C for x = 0, slightly increased to 44°C for x = 0.005, and then greatly decreased as x increased to 0.020.
Some of the metrics are blocked by your
consent settings
PHASE FORMATION AND ELECTRICAL PROPERTIES OF BCLTS CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION TECHNIQUE
(2025-01-01)
Somsri, Widchaya
;
Charoenthai, Nipaphat
;
Sutthapintu, Aekkasit
;
Noisak, Jitrawan
;
Vittayakorn, Naratip
Lead-free Ba<inf>0.93</inf>Ca<inf>0.04</inf>La<inf>0.03</inf>Ti<inf>0.90</inf>Sn<inf>0.10</inf>O<inf>3</inf> (BCLTS) ceramics were fabricated via solid-state combustion technique. The BCLTS powders were calcined in a temperature range of 1075-1175°C for 2h and sintered in a temperature range of 1350-1450°C for 2h. The BCLTS powders exhibited a pure perovskite phase when calcined above 1150°C. All BCLTS ceramic samples displayed a perovskite structure with coexisting cubic and tetragonal phases, with a secondary phase observed only at 1450°C. The growth of grain size was increased with increasing sintering temperature (0.42 to 0.65 μm.). The highest dielectric and ferroelectric properties (ε<inf>r</inf>=3047, tan δ<inf>r</inf> = 0.029, P<inf>max</inf> = 9.52 μC/cm2, P<inf>r</inf> = 0.48 μC/cm2, E<inf>c</inf>= 1.04 kV/cm) were obtained at the sintering temperature of 1400°C. The altered phase structure in this research, compared to earlier studies, results in distinct outcomes for the dielectric and ferroelectric properties.
Some of the metrics are blocked by your
consent settings
EFFECT OF FIRING TEMPERATURE ON THE PHASE FORMATION, MICROSTRUCTURE, AND ELECTRICAL PROPERTIES OF BST-BZN CERAMICS
(2025-01-01)
Somsri, Widchaya
;
Duangkeaw, Panadda
;
Sumang, Rattiphorn
;
Pulphol, Phieraya
;
Vittayakorn, Naratip
Lead-free 0.88Ba0.8Sr0.2TiO3-0.12Bi(Zn2/3Nb1/3)O3 (BST-BZN) ceramics were prepared by the solid-state combustion technique, using glycine as fuel. The BST-BZN ceramics were calcined between 900–1100°C for 2 h and sintered between 1300–1400°C for 2 h. A pure perovskite phase with a pseudo-cubic structure was observed by XRD and confirmed by the Rietveld refinement technique. The average particle and grain sizes tended to increase with increased calcination and sintering temperatures. The measured density was in the range of 5.65–5.90 g/cm3. The dielectric constant (εr) and dielectric loss (tan δr) decreased with increased sintering temperatures, up to 1350°C and then increased. The energy storage density (Wtotal) and energy storage efficiency (η) of the ceramics were 0.488 J/cm3 and 94.1% measured at 100 kV/cm, respectively, obtained by the sample sintered at 1375°C
Some of the metrics are blocked by your
consent settings
PHASE FORMATION AND ELECTRICAL PROPERTIES OF Ba0.91Ca0.09Ti0.916Sn0.084O3-0.1WT%ZnO -0.1WT%MnO2 LEAD-FREE FERROELECTRIC CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION METHOD
(2025-01-01)
Yimsabai, Sununta
;
Somsri, Widchaya
;
Vittayakorn, Naratip
;
Charoenthai, Nipaphat
;
Suthapintu, Aekasit
This work investigated the effect of firing temperatures on the phase formation, microstructure, and electrical properties of Ba0.91Ca0.09Ti0.916Sn0.084O3-0.1wt%ZnO-0.1wt%MnO2 (BCTS-ZnMn) lead-free ferroelectric ceramics synthesized via the solid-state combustion method. Glycine was used as fuel to reduce the synthesis temperature. The samples were calcined at temperatures from 1050 to 1250°C (in 50°C increments) for 3 h and sintered from 1250 to 1450°C (in 50°C increments) for 3 h. A pure perovskite phase was found in the powders calcined above 1100°C. The phase structure, microstructure, dielectric and ferroelectric properties of the ceramics were examined. The X-ray diffraction (XRD) analysis for the ceramics revealed the presence of tetragonal (T) and orthorhombic (O) phases in all the ceramics. The average particle size and average grain size increased with increasing firing temperatures. The density, dielectric constant at the Curie temperature (ɛc), Pr and Ps tended to increase with increasing sintering temperatures, up to 1400°C, and then decreased at 1450°C. The ceramic sintered at 1400°C exhibited the highest density (5.89 g/cm3), dielectric response (ɛc = 13324) and good ferroelectric behavior (Pr = 8.67 μC/cm2, Ps = 17.92 μC/cm2 and Ec = 0.99 kV/cm).
Some of the metrics are blocked by your
consent settings
Phase formation and electrical properties of SBNLT ceramics prepared via combustion technique
(2023-01-01)
Sinkruason, Thanapon
;
Luangpangai, Anupong
;
Charoenthai, Nipaphat
;
Rittidech, Aurawan
;
Pulphol, Phieraya
This report investigates the effect of firing temperatures on the phase formation, microstructure, electrical, and energy storage properties of lead-free Sr<inf>0.3</inf>(Bi<inf>0.7</inf>Na<inf>0.67</inf>Li<inf>0.03</inf>)<inf>0.5</inf>TiO<inf>3</inf> (SBNLT) ceramics, synthesised by combustion technique. The samples were calcined between 700°C and 900°C for 2 h and sintered between 1100°C and 1200°C for 2 h. The ceramics exhibited coexisting rhombohedral and tetragonal phases, which were confirmed by the Rietveld refinement technique. A morphotropic phase boundary (MPB) of the rhombohedral and tetragonal phases, with a ratio of 49:51, was obtained at the sintering temperature of 1175°C. The highest maximum dielectric constant (ε <inf>max</inf>= 4667), polarisation (P <inf>max</inf>= 28.80 µC/cm2) and energy density (W = 0.95 J/cm3), with a breakdown strength of 70 kV/cm, were achieved from the sample sintered at 1175°C.
Some of the metrics are blocked by your
consent settings
Phase Formation, Microstructure and Electric Properties of Vanadium Doped Lead-Free BaTi0.91Sn0.09O3 Ceramics
(2023-01-01)
Pattanakasem, Wiwat
;
Charoenthai, Nipaphat
;
Vittayakorn, Naratip
;
Bongkarn, Theerachai
Lead-free Ba(Ti<inf>0.91</inf>Sn<inf>0.09</inf>)<inf>1-x</inf>V<inf>x</inf>O<inf>3</inf> (BTSV, x = 0, 0.005,0.010, 0.015, and 0.020) ceramics were prepared by the conventional solid-state sintering method with a calcination temperature of 1200 °C for 2 h and a sintering temperature between 1350 °C and 1400 °C for 4 h. The effect of vanadium (V) doping on the phase formation, microstructure and electrical properties of the ceramics was investigated. X-ray diffraction (XRD) measurements revealed that the ceramics with x = 0 and 0.005 had pure perovskite structures with no detectable impurity, while the ceramics with x ≥ 0.010 exhibited perovskite structures and had secondary impurity phases. Coexisting orthorhombic and tetragonal phases were observed and the Rietveld refinement analysis suggested that the tetragonal phase increased with increased V5+ substitution. When x increased from 0 to 0.010, the average grain size increased from 47 to 62 µm and then dropped, while the density (ρ) decreased from 5.98 to 5.64 g/cm3 when x increased. Furthermore, the BTSV ceramics exhibited increased porosity, Curie temperatures (T <inf>C</inf> ∼ 42 °C to 52 °C) and coercive field (E <inf>c</inf>), while the dielectric constant at the Curie temperature (ε<inf>C</inf>) and the remnant polarization (P <inf>r</inf>) of the ceramics decreased (∼18023 to 6110 and ∼7.42 to 4.88 µC/cm2, respectively) when V5+ doping increased.
Some of the metrics are blocked by your
consent settings
Phase Structure, Microstructure, and Electrical Properties of Bi0.47Na0.47Ba0.06TiO3 Ceramics with (LiNb)4+ Substituted into B-Sites
(2023-01-01)
Luangpangai, Anupong
;
Thatawong, Bhoowadol
;
Charoenthai, Nipaphat
;
Vittayakorn, Naratip
;
Bongkarn, Theerachai
Due to the substitution of complex ions into B-sites is very interesting in recent, lead-free Bi<inf>0.47</inf>Na<inf>0.47</inf>Ba<inf>0.06</inf>Ti<inf>1−</inf><inf>x</inf> (LiNb) <inf>x</inf> O<inf>3</inf> (BNBT<inf>1−</inf><inf>x</inf> LN <inf>x</inf>) ceramics (with x = 0–0.04) were fabricated by the solid-state combustion method. The influence of (LiNb)4+ (x) on the phase structure, microstructure, and electrical properties was investigated. The X-ray diffraction (XRD) patterns exhibited a pure perovskite structure for all specimens. Coexisting rhombohedral and tetragonal phases were observed in all samples and the tetragonal phase increased with increased x, as analyzed by the Rietveld refinement method. The morphology of the BNBT<inf>1−</inf><inf>x</inf> LN <inf>x</inf> ceramics, obtained by scanning electron microscopy (SEM), revealed almost-round grain shapes and anisotropic grain growth. The density and average grain sizes decreased from 5.84 to 5.54 g/cm3 and 1.7 to 0.9 µm, respectively, when x increased from 0 to 0.04. The grain size distribution decreased with increased (LiNb)4+ content. A reduction in the dielectric properties was observed, due to the phase ratio changing away from a morphotropic phase boundary (MPB), an inferior microstructure, and low density caused by (LiNb)4+ substitution. The (LiNb)4+ substitution induced the transition from non-ergodic relaxor to ergodic relaxor ferroelectric state.
Some of the metrics are blocked by your
consent settings
Effect of substitution of (NiNb)4+ into B-sites on the phase formation, microstructure and electrical properties of Bi0.47Na0.47Ba0.06TiO3 ceramics
(2022-01-01)
Luangpangai, Anupong
;
Bhupaijit, Pamornnarumol
;
Charoenthai, Nipaphat
;
Vittayakorn, Naratip
;
Thountom, Sarawut
Bi<inf>0.47</inf>Na<inf>0.47</inf>Ba<inf>0.06</inf>Ti<inf>1-x</inf>(Ni<inf>1/3</inf>Nb<inf>2/3</inf>)<inf>x</inf>O<inf>3</inf> ceramics (abbreviated as BNBT<inf>1-x</inf>(NN)<inf>x</inf>, x = 0, 0.01, 0.03 and 0.05) were synthesized by solid-state combustion. The effect of x on the phase formation, microstructure and electrical properties of BNBT<inf>1-x</inf>(NN)<inf>x</inf> ceramics was examined. The XRD pattern indicated the coexistence of rhombohedral and tetragonal phases in all the specimens. Moreover, Rietveld refinement confirmed that the tetragonal phase increased from 47 to 71% when x increased from 0 to 0.05. The morphology of BNBT<inf>1-x</inf>(NN)<inf>x</inf> ceramics was observed by SEM and the ceramics grains showed polygonal shapes and the grain growth tended to be anisotropic. With (NiNb)4+ substitution, the average grain sized decreased rapidly from 1.7 to 1.0 µm and the grain size distribution was narrower as the amount of (NiNb)4+ increased. The density, remnant polarization (P<inf>r</inf>) and coercive field (E<inf>c</inf>) rapidly decreased with increasing x. A significant decrease in the ferroelectric properties was caused by the increasing tetragonal phase.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results