Pub Date : 2023-04-03DOI: 10.1080/21870764.2023.2203991
H. Kwon, Y. Yoo, Youn-Min Park, U. Nam, E. Byon
ABSTRACT In this study, Al2O3-based coatings with varying TiO2 contents (0, 3, 13, and 40%) were fabricated using atmospheric plasma spraying technique. To compare the superiority of the samples, their mechanical (Vickers hardness and adhesion strength) and thermal properties (thermal conductivity and thermal shock resistance) were characterized. As observed, Al2O3-40%TiO2 (A-40T) coating exhibited relatively inferior mechanical properties but superior thermal insulation and thermal shock resistance at 600°C. According to the microstructure and phase analysis, this finding is attributed to the special phase, Al2TiO5, and preexisting microcracks inside the coating. Thus, A-40T manifested excellent characteristics for thermal insulation application compared with pure Al2O3 and low-TiO2 content coatings.
{"title":"Effect of TiO2 on mechanical and thermal properties of Al2O3-based coating via atmospheric plasma spraying","authors":"H. Kwon, Y. Yoo, Youn-Min Park, U. Nam, E. Byon","doi":"10.1080/21870764.2023.2203991","DOIUrl":"https://doi.org/10.1080/21870764.2023.2203991","url":null,"abstract":"ABSTRACT In this study, Al2O3-based coatings with varying TiO2 contents (0, 3, 13, and 40%) were fabricated using atmospheric plasma spraying technique. To compare the superiority of the samples, their mechanical (Vickers hardness and adhesion strength) and thermal properties (thermal conductivity and thermal shock resistance) were characterized. As observed, Al2O3-40%TiO2 (A-40T) coating exhibited relatively inferior mechanical properties but superior thermal insulation and thermal shock resistance at 600°C. According to the microstructure and phase analysis, this finding is attributed to the special phase, Al2TiO5, and preexisting microcracks inside the coating. Thus, A-40T manifested excellent characteristics for thermal insulation application compared with pure Al2O3 and low-TiO2 content coatings.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46758831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-03DOI: 10.1080/21870764.2023.2203635
M. Rahman
ABSTRACT Due to its multifunctional properties, BaTiO3(BT) is a crucial ceramic material in the semiconductor market. The development of doping techniques has received considerable attention in recent years as efforts continue to enhance the attractive qualities of BaTiO3 and broaden the range of modern technologies in which it can be used. The synthesis method and doping components must be carefully chosen in order to produce appropriate BaTiO3 particles with high purity and suitable grain size that are critical for the desired end applications of synthesized doped BaTiO3. Doping can be performed in either the A site or B site or in both sites proportionally. This brief review has been compiled to increase our understanding of the doping sites as well as the possible applications based on the previous literature.
{"title":"Understanding of doping sites and versatile applications of heteroatom modified BaTiO3 ceramic","authors":"M. Rahman","doi":"10.1080/21870764.2023.2203635","DOIUrl":"https://doi.org/10.1080/21870764.2023.2203635","url":null,"abstract":"ABSTRACT Due to its multifunctional properties, BaTiO3(BT) is a crucial ceramic material in the semiconductor market. The development of doping techniques has received considerable attention in recent years as efforts continue to enhance the attractive qualities of BaTiO3 and broaden the range of modern technologies in which it can be used. The synthesis method and doping components must be carefully chosen in order to produce appropriate BaTiO3 particles with high purity and suitable grain size that are critical for the desired end applications of synthesized doped BaTiO3. Doping can be performed in either the A site or B site or in both sites proportionally. This brief review has been compiled to increase our understanding of the doping sites as well as the possible applications based on the previous literature.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47895963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Ultra-high-temperature ceramics are required for many aerospace applications. In this work, HfB2-30 vol.% HfC and HfB2-26 vol.% HfC-43 vol.% MoB high-density composites were prepared by one-step in-situ reactive spark plasma sintering (R-SPS) using Hf, B4C and Mo powders as starting materials. The influences of sintering temperature on the densification mechanism, microstructural evolution, mechanical properties and oxidation resistance of the composites were thoroughly investigated. The results demonstrate that the raw materials undergo a complete chemical reaction to form new binary HfB2-HfC and ternary HfB2-HfC-MoB composite structures at a temperature of 1300°C. The HfB2-HfC and HfB2-HfC-MoB composites prepared at the optimal conditions (pressure = 50 MPa, temperature = 1800°C, holding time = 5 min) had highre densities of 97% and 98%, respectively. The Vickers hardness, Young’s modulus and fracture toughness of the HfB2-HfC composite were 18.3 GPa, 525 GPa and 6.34 MPa·m1/2, respectively. However, after molybdenum was added, the Vickers hardness of the ternary HfB2-HfC-MoB composite increased to 19.4 GPa but its fracture toughness decreased slightly to 6.1 MPa·m1/2. Compared with the binary composite, the ternary composite exhibited a low and thermally stable oxidation rate up to a temperature of 1400°C, and the test was conducted in air atmosphere.
{"title":"Preparation and properties of HfB2-HfC and HfB2-HfC-MoB composites by reactive spark plasma sintering","authors":"Yangshuo Bai, Weixia Shen, Chao Fang, Liangchao Chen, Qianqian Wang, Biao Wan, X. Jia, Yue Zhang, Zhuangfei Zhang","doi":"10.1080/21870764.2023.2198860","DOIUrl":"https://doi.org/10.1080/21870764.2023.2198860","url":null,"abstract":"ABSTRACT Ultra-high-temperature ceramics are required for many aerospace applications. In this work, HfB2-30 vol.% HfC and HfB2-26 vol.% HfC-43 vol.% MoB high-density composites were prepared by one-step in-situ reactive spark plasma sintering (R-SPS) using Hf, B4C and Mo powders as starting materials. The influences of sintering temperature on the densification mechanism, microstructural evolution, mechanical properties and oxidation resistance of the composites were thoroughly investigated. The results demonstrate that the raw materials undergo a complete chemical reaction to form new binary HfB2-HfC and ternary HfB2-HfC-MoB composite structures at a temperature of 1300°C. The HfB2-HfC and HfB2-HfC-MoB composites prepared at the optimal conditions (pressure = 50 MPa, temperature = 1800°C, holding time = 5 min) had highre densities of 97% and 98%, respectively. The Vickers hardness, Young’s modulus and fracture toughness of the HfB2-HfC composite were 18.3 GPa, 525 GPa and 6.34 MPa·m1/2, respectively. However, after molybdenum was added, the Vickers hardness of the ternary HfB2-HfC-MoB composite increased to 19.4 GPa but its fracture toughness decreased slightly to 6.1 MPa·m1/2. Compared with the binary composite, the ternary composite exhibited a low and thermally stable oxidation rate up to a temperature of 1400°C, and the test was conducted in air atmosphere.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43871138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT A high purity Al2O3 ceramic (HPAOC) metallizing strategy was developed via gradient coating process of metallizing pastes with different ratios of Mo to manganese glass (MnG) contents, to improve the wettability and reactivity of metallized layer (ML) to the ceramic substrate and the secondary metallizing layer or sealed metals. Self-made HPAOC samples firstly coated by a layer of metallizing paste with a lower proportion of Mo:MnG and superposed a layer of metallizing paste with a higher proportion of Mo:MnG were fired at 1450°C in hydrogen atmosphere. The crystal phase structure, microstructure and element distribution of the metallized samples wer characterized by XRD, SEM and EDS. The results of sealing properties show that the tensile sealing strength of as high as 121MPa and the He leakage rate of as low as 4.2 × 10−11 Pa.m3/s can be obtained of the sealed joints of the as-metallized HPAOC and Kovar.
{"title":"High purity Al2O3 ceramic:Metallizing strategy, microstructure and sealing properties","authors":"Dongcai Li, Cang He, Yong Sheng Wang, Weifeng Su, Fengjun Zhang, Haiyan Xu","doi":"10.1080/21870764.2023.2195288","DOIUrl":"https://doi.org/10.1080/21870764.2023.2195288","url":null,"abstract":"ABSTRACT A high purity Al2O3 ceramic (HPAOC) metallizing strategy was developed via gradient coating process of metallizing pastes with different ratios of Mo to manganese glass (MnG) contents, to improve the wettability and reactivity of metallized layer (ML) to the ceramic substrate and the secondary metallizing layer or sealed metals. Self-made HPAOC samples firstly coated by a layer of metallizing paste with a lower proportion of Mo:MnG and superposed a layer of metallizing paste with a higher proportion of Mo:MnG were fired at 1450°C in hydrogen atmosphere. The crystal phase structure, microstructure and element distribution of the metallized samples wer characterized by XRD, SEM and EDS. The results of sealing properties show that the tensile sealing strength of as high as 121MPa and the He leakage rate of as low as 4.2 × 10−11 Pa.m3/s can be obtained of the sealed joints of the as-metallized HPAOC and Kovar.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42813567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-15DOI: 10.1080/21870764.2023.2186006
Lihua Lv, Zhanmin Wang, Xiying Cao, Shuang Han, Chaochao Ju, Jun Han
ABSTRACT Refractories subject to loading and unloading repeatedly because of physical effects and thermal stress attack in the service process, which is an important issue shortening the service life of the thermal equipment. Therefore, researches of predicting the service life of refractories under cyclic loading have the guiding significance. The present work investigated the synthesis of ZnAl2O4 and discussed its effects on the alumina castables. The results show that the optimized generation temperature of ZnAl2O4 phase is 1400°C and the hysteresis loop in the curves of cyclic loading reveals a general trend of first sparse and then dense. The cycle times of the specimen with 3 wt.% ZnAl2O4 is 50 times, and the time from starting to loop to fracture is about 4300 s. The fatigue resistance of the specimen with 3 wt.% ZnAl2O4 is superior to ZA-0 and ZA-1.5. The new method of cyclic loading was innovatively adopted in refractories, which provide data and theoretical support for the thermal shock evaluation methods.
{"title":"Preparation of ZnAl2O4 and its effect on fatigue resistance of alumina castables","authors":"Lihua Lv, Zhanmin Wang, Xiying Cao, Shuang Han, Chaochao Ju, Jun Han","doi":"10.1080/21870764.2023.2186006","DOIUrl":"https://doi.org/10.1080/21870764.2023.2186006","url":null,"abstract":"ABSTRACT Refractories subject to loading and unloading repeatedly because of physical effects and thermal stress attack in the service process, which is an important issue shortening the service life of the thermal equipment. Therefore, researches of predicting the service life of refractories under cyclic loading have the guiding significance. The present work investigated the synthesis of ZnAl2O4 and discussed its effects on the alumina castables. The results show that the optimized generation temperature of ZnAl2O4 phase is 1400°C and the hysteresis loop in the curves of cyclic loading reveals a general trend of first sparse and then dense. The cycle times of the specimen with 3 wt.% ZnAl2O4 is 50 times, and the time from starting to loop to fracture is about 4300 s. The fatigue resistance of the specimen with 3 wt.% ZnAl2O4 is superior to ZA-0 and ZA-1.5. The new method of cyclic loading was innovatively adopted in refractories, which provide data and theoretical support for the thermal shock evaluation methods.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43623625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-15DOI: 10.1080/21870764.2023.2186842
Mizuki Watanabe, M. Itoh, Ryohei Oka, S. Ida, Toshiyuki Masui
ABSTRACT Neodymium-doped phosphates, (Nd1-x Gd x )0.33Zr2(PO4)3 (0 ≤ x ≤ 1), were synthesized by co-precipitation. (Nd1-x Gd x )0.33Zr2(PO4)3 was obtained as a single-phase and was confirmed to be a NASICON-type structure consisting of a three-dimensional network of PO4 tetrahedra sharing corners with ZrO6 octahedra. The particle size of the (Nd1-x Gd x )0.33Zr2(PO4)3 samples was in the nanoscale, which is suitable for in vivo optical imaging. The (Nd1-x Gd x )0.33Zr2(PO4)3 samples showed characteristic luminescence corresponding to the f – f transitions of Nd3+. The highest emission intensity at 1072 nm with excitation at 824 nm was observed for (Nd0.75Gd0.25)0.33Zr2(PO4)3, which was 4.5 times higher than that of Nd0.33Zr2(PO4)3. The near-infrared (NIR) emission intensity of this nanophosphor was significantly higher than that of indocyanine green, which is actually used as an in vivo optical probe reagent.
{"title":"Nd-doped NASICON-type nanophosphors for near-infrared excitation and emission","authors":"Mizuki Watanabe, M. Itoh, Ryohei Oka, S. Ida, Toshiyuki Masui","doi":"10.1080/21870764.2023.2186842","DOIUrl":"https://doi.org/10.1080/21870764.2023.2186842","url":null,"abstract":"ABSTRACT Neodymium-doped phosphates, (Nd1-x Gd x )0.33Zr2(PO4)3 (0 ≤ x ≤ 1), were synthesized by co-precipitation. (Nd1-x Gd x )0.33Zr2(PO4)3 was obtained as a single-phase and was confirmed to be a NASICON-type structure consisting of a three-dimensional network of PO4 tetrahedra sharing corners with ZrO6 octahedra. The particle size of the (Nd1-x Gd x )0.33Zr2(PO4)3 samples was in the nanoscale, which is suitable for in vivo optical imaging. The (Nd1-x Gd x )0.33Zr2(PO4)3 samples showed characteristic luminescence corresponding to the f – f transitions of Nd3+. The highest emission intensity at 1072 nm with excitation at 824 nm was observed for (Nd0.75Gd0.25)0.33Zr2(PO4)3, which was 4.5 times higher than that of Nd0.33Zr2(PO4)3. The near-infrared (NIR) emission intensity of this nanophosphor was significantly higher than that of indocyanine green, which is actually used as an in vivo optical probe reagent.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47142041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-15DOI: 10.1080/21870764.2023.2186008
M. Kitiwan, D. Atong, F. Endo, T. Goto
ABSTRACT Fully dense Al2TiO5–Al2O3–TiN (ATN) composites were fabricated by reactive sintering using spark plasma sintering at 1400°C for 5 min under 100 MPa in vacuum. An equimolar ratio of Al2O3:TiO2 was used as the starting powder, while the addition of 0–36 mol% AlN was investigated. The thermodynamic calculation indicates that the initial reaction was that of TiO2 and AlN, forming TiN and Al2O3, and then the remaining TiO2 reacted with Al2O3 to produce Al2TiO5. With the increase in AlN precursor, Al2TiO5 gradually decreased, while Al2O3 and TiN increased. The lattice parameters of Al2TiO5 were enlarged with AlN addition, implying the incorporation of N atoms in the Al2TiO5 unit cell. The addition of AlN effectively produced fully densified bodies with small grain size, and microcrack-free, which therefore enhanced the mechanical properties of ATN composites. At 36 mol% AlN addition, the composite shows Vickers hardness and fracture toughness of 16.26 ± 1.61 GPa and 5.20 ± 0.46 MPa.m1/2, respectively.
{"title":"Effect of AlN addition on the reaction sintering of Al2TiO5 composites fabricated by spark plasma sintering","authors":"M. Kitiwan, D. Atong, F. Endo, T. Goto","doi":"10.1080/21870764.2023.2186008","DOIUrl":"https://doi.org/10.1080/21870764.2023.2186008","url":null,"abstract":"ABSTRACT Fully dense Al2TiO5–Al2O3–TiN (ATN) composites were fabricated by reactive sintering using spark plasma sintering at 1400°C for 5 min under 100 MPa in vacuum. An equimolar ratio of Al2O3:TiO2 was used as the starting powder, while the addition of 0–36 mol% AlN was investigated. The thermodynamic calculation indicates that the initial reaction was that of TiO2 and AlN, forming TiN and Al2O3, and then the remaining TiO2 reacted with Al2O3 to produce Al2TiO5. With the increase in AlN precursor, Al2TiO5 gradually decreased, while Al2O3 and TiN increased. The lattice parameters of Al2TiO5 were enlarged with AlN addition, implying the incorporation of N atoms in the Al2TiO5 unit cell. The addition of AlN effectively produced fully densified bodies with small grain size, and microcrack-free, which therefore enhanced the mechanical properties of ATN composites. At 36 mol% AlN addition, the composite shows Vickers hardness and fracture toughness of 16.26 ± 1.61 GPa and 5.20 ± 0.46 MPa.m1/2, respectively.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43249336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/21870764.2023.2174243
Jeongyoul Kim, Jong-Chan Lim, Sang‐il Kim, Seong-Mee Hwang, W. Shin, Heesun Yang, Kyu Hyoung Lee, Hyun-sik Kim
ABSTRACT The effects of varying calcination temperature, K content, and the number of calcination steps in the dielectric performance of KCa2Nb3O10 synthesized via solid-state reaction are investigated. Adding an extra calcination step at 500°C followed by another calcination at 1100°C suppressed the formation of secondary phases while maximizing the relative density (95%) and the average grain area (2.12 μm2). The first calcination at 500°C ensures the formation of intermediate phases (KNbO3 and Ca2Nb2O7), which are prerequisites for single-phase KCa2Nb3O10 synthesis. A significantly high dielectric constant of 352 at 100k Hz is achieved in the two-step calcined sample despite the low sintering temperature of 1250°C. The highest resistivity of the two-step calcined sample (2 × 108 Ω cm) obtained from complex impedance analysis supports its lowest dielectric loss (0.034 at 100k Hz). When the two-step calcined KCa2Nb3O10 powder is exfoliated, much higher dielectric properties of Ca2Nb3O10 nanosheets are expected.
{"title":"Impact of two-step calcination on microstructure, phase, electronic, and dielectric properties of KCa2Nb3O10 bulk layered perovskite","authors":"Jeongyoul Kim, Jong-Chan Lim, Sang‐il Kim, Seong-Mee Hwang, W. Shin, Heesun Yang, Kyu Hyoung Lee, Hyun-sik Kim","doi":"10.1080/21870764.2023.2174243","DOIUrl":"https://doi.org/10.1080/21870764.2023.2174243","url":null,"abstract":"ABSTRACT The effects of varying calcination temperature, K content, and the number of calcination steps in the dielectric performance of KCa2Nb3O10 synthesized via solid-state reaction are investigated. Adding an extra calcination step at 500°C followed by another calcination at 1100°C suppressed the formation of secondary phases while maximizing the relative density (95%) and the average grain area (2.12 μm2). The first calcination at 500°C ensures the formation of intermediate phases (KNbO3 and Ca2Nb2O7), which are prerequisites for single-phase KCa2Nb3O10 synthesis. A significantly high dielectric constant of 352 at 100k Hz is achieved in the two-step calcined sample despite the low sintering temperature of 1250°C. The highest resistivity of the two-step calcined sample (2 × 108 Ω cm) obtained from complex impedance analysis supports its lowest dielectric loss (0.034 at 100k Hz). When the two-step calcined KCa2Nb3O10 powder is exfoliated, much higher dielectric properties of Ca2Nb3O10 nanosheets are expected.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46247476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/21870764.2023.2181280
N. Cruz Santiago, E. Ramírez Morales, T. González Sánchez, R. Castillo Palomera, L. Rojas Blanco, G. Hernández Galvez, E. Miranda Mandujano, C. Ricárdez Jiménez, A. Trujillo Narcía, Omar Sarracino Martínez
ABSTRACT Binary sulfides were deposited by sequential thermal evaporation with the stacking order glass/CuS/SnS/ZnS and subsequently subjected to a sulfurization-crystallization process, considering two thermal treatment time intervals, 5 and 20 min. The objective of implementing different annealing durations was to identify the best conditions to form CZTS films in the pure kesterite phase. After being subjected to the annealing, the films show structural characteristics of the kesterite phase. However, XRD data showed that prolonged annealing causes degradation of the kesterite phase, leading to the formation of traces of CuS and Cu5Sn2S7. The films annealed for shorter duration, in this case 5 min, present a denser and more uniform surface morphology, better degree of preferential orientation, small Urbach energy of 0.302 eV, and higher photosensitivity. The band gap of the films was 1.46 eV and 1.53 eV for annealing durations 5 and 20 min, respectively. Graphical abstract
{"title":"Evolution of the Cu2ZnSnS4 phase based on the sulfurization-crystallisation duration of the CuS/SnS/ZnS stack formed by thermal evaporation","authors":"N. Cruz Santiago, E. Ramírez Morales, T. González Sánchez, R. Castillo Palomera, L. Rojas Blanco, G. Hernández Galvez, E. Miranda Mandujano, C. Ricárdez Jiménez, A. Trujillo Narcía, Omar Sarracino Martínez","doi":"10.1080/21870764.2023.2181280","DOIUrl":"https://doi.org/10.1080/21870764.2023.2181280","url":null,"abstract":"ABSTRACT Binary sulfides were deposited by sequential thermal evaporation with the stacking order glass/CuS/SnS/ZnS and subsequently subjected to a sulfurization-crystallization process, considering two thermal treatment time intervals, 5 and 20 min. The objective of implementing different annealing durations was to identify the best conditions to form CZTS films in the pure kesterite phase. After being subjected to the annealing, the films show structural characteristics of the kesterite phase. However, XRD data showed that prolonged annealing causes degradation of the kesterite phase, leading to the formation of traces of CuS and Cu5Sn2S7. The films annealed for shorter duration, in this case 5 min, present a denser and more uniform surface morphology, better degree of preferential orientation, small Urbach energy of 0.302 eV, and higher photosensitivity. The band gap of the films was 1.46 eV and 1.53 eV for annealing durations 5 and 20 min, respectively. Graphical abstract","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44215286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/21870764.2022.2163962
Jing-Siang Jhan, Chih‐Cheng Chen, Yu-Chih Liu, H. Hsiang
ABSTRACT Gel casting technology and a two-stage sintering process were used to produce yttria-stabilized tetragonal zirconia (YTZP) ceramics with excellent mechanical properties. A carbonic acid-based polyelectrolyte dispersant was used as a dispersant to prepare a well-dispersed nano-sized (94 nm) zirconia slurry with a high solid content (45 vol%) for gel casting. The functional carboxyl groups of the polyelectrolyte dispersant reacted with epoxy monomer (ethylene glycol diglycidyl ether, EGDGE) as it was added to the slurry, resulting in a decrease in gelling incubation time and an increase in viscosity, resulting in gel casting failure. Adding hydroquinone (HQ) to the slurry can cause polymerization to be delayed and the gel-casting working time to be extended. To control grain growth, a two-stage sintering process was used. The temperature for the first stage of sintering was set at 1300°C, then lowered to 1240°C and soaked for 24 h in the second stage to achieve a relative density of greater than 99%. The two-stage sintered sample has a Vickers hardness of 15.2 GPa, fracture toughness of 7.8 MPa.m1/2, and flexural strength of 771 MPa.
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