Takumi Yabuzaki, Miho Sato, Hanseul Kim, Kenta Watanabe, Naoki Matsui, Kota Suzuki, Satoshi Hori, Kazuhiro Hikima, Satoshi Obokata, Hiroyuki Muto, Atsunori Matsuda, Ryoji Kanno, Masaaki Hirayama
Sulfide-type solid electrolytes for all-solid-state lithium-ion batteries are required to have high ionic conductivity, high (electro) chemical stability, and suitable mechanical properties. Compositing different materials is widely performed in developing multifunctional materials. However, only a few studies have investigated sulfide electrolytes due to the concern of lowering ionic conductivity. In this study, composite electrolytes comprising Li10GeP2S12 (LGPS)-type electrolytes and nanosized Al2O3 are fabricated by a solid-state reaction. Al2O3 particles are mainly located in the voids between LGPS particles, whereas very limited oxygen content is substituted for sulfur in the LGPS structure. LGPS–Al2O3 composites exhibit ionic conductivities of ∼5 mS cm−1 without significant changes by compositing Al2O3. LGPS–Al2O3 composites are softer and have higher atmospheric stability than uncomposed LGPS. All solid-state cells that use air-exposed LGPS–Al2O3 as a separator layer exhibit an improved cycle retention compared with that using air-exposed LGPS. These results demonstrate that electrolyte compositing is an effective means of improving other properties while maintaining high lithium ionic conductivity.
{"title":"Electrochemical and mechanical properties and chemical stability of Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub>/Al<sub>2</sub>O<sub>3</sub> composite electrolytes","authors":"Takumi Yabuzaki, Miho Sato, Hanseul Kim, Kenta Watanabe, Naoki Matsui, Kota Suzuki, Satoshi Hori, Kazuhiro Hikima, Satoshi Obokata, Hiroyuki Muto, Atsunori Matsuda, Ryoji Kanno, Masaaki Hirayama","doi":"10.2109/jcersj2.23070","DOIUrl":"https://doi.org/10.2109/jcersj2.23070","url":null,"abstract":"Sulfide-type solid electrolytes for all-solid-state lithium-ion batteries are required to have high ionic conductivity, high (electro) chemical stability, and suitable mechanical properties. Compositing different materials is widely performed in developing multifunctional materials. However, only a few studies have investigated sulfide electrolytes due to the concern of lowering ionic conductivity. In this study, composite electrolytes comprising Li10GeP2S12 (LGPS)-type electrolytes and nanosized Al2O3 are fabricated by a solid-state reaction. Al2O3 particles are mainly located in the voids between LGPS particles, whereas very limited oxygen content is substituted for sulfur in the LGPS structure. LGPS–Al2O3 composites exhibit ionic conductivities of ∼5 mS cm−1 without significant changes by compositing Al2O3. LGPS–Al2O3 composites are softer and have higher atmospheric stability than uncomposed LGPS. All solid-state cells that use air-exposed LGPS–Al2O3 as a separator layer exhibit an improved cycle retention compared with that using air-exposed LGPS. These results demonstrate that electrolyte compositing is an effective means of improving other properties while maintaining high lithium ionic conductivity.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372801","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}
The copper (Cu) valence greatly influences the transition temperature (Tc) in cuprate superconductors. According to the charge neutralization rule, the Cu valence is calculated from the oxygen content. Previously, we developed the dissolved oxygen (DO) method as a novel oxygen measurement method for La2−xSrxCuO4 and YBa2Cu3Oy (YBCO) using a new DO sensor. The measurement time of the DO method is about one-third that of the standard iodometric method, but the difference in the measured Cu valence for YBCO is 0.039. Herein we report that a more accurate method, which combines the dissolved chlorine method and the corrected DO method, improves this difference to 0.013.
{"title":"A more accurate method to measure the oxygen content in YBa<sub>2</sub>Cu<sub>3</sub>O<i><sub>y</sub></i> superconductors","authors":"Yuliang Wei, Shiro Kambe","doi":"10.2109/jcersj2.23108","DOIUrl":"https://doi.org/10.2109/jcersj2.23108","url":null,"abstract":"The copper (Cu) valence greatly influences the transition temperature (Tc) in cuprate superconductors. According to the charge neutralization rule, the Cu valence is calculated from the oxygen content. Previously, we developed the dissolved oxygen (DO) method as a novel oxygen measurement method for La2−xSrxCuO4 and YBa2Cu3Oy (YBCO) using a new DO sensor. The measurement time of the DO method is about one-third that of the standard iodometric method, but the difference in the measured Cu valence for YBCO is 0.039. Herein we report that a more accurate method, which combines the dissolved chlorine method and the corrected DO method, improves this difference to 0.013.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372805","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}
Adding carbon nanotubes (CNTs) into ceramics is an important way to promote toughness. Crystalline defects existing in materials play a significant role in affecting both their mechanical and functional performances because they bring symmetry breaking of the periodic lattice structures. For CNTs existing in real ceramic materials, which almost appear as polycrystalline forms, the most notable defects are the grain boundaries (GBs) which consist of defect cores of dislocations. It is of engineering importance to investigate the effects of these defect cores of GBs on the strength of the polycrystalline CNTs to promote the composites’ performances. The variety of grain orientations of the polycrystalline CNTs allows the GBs to have various misorientations and different arrangements of the defect cores of dislocations at the GBs, which causes disparity in the stress fields near the GBs under an external stress condition, thus making distinguishable effects on the strength. While effective rules have been established for graphene (GP) GBs to predict the tensile strengths of GP GBs with different misorientations, the effects of misorientation and curvature on the strength of CNT GBs have yet to be reported. This work studied these effects by molecular dynamics (MD) simulation. The results illustrate that the misorientation and temperature have much more significant effects than the curvature on the strength of CNT GBs, and verified a consistent tendency of the misorientation-strength relationship of the CNT GBs with the corresponding GP GBs. The CNT GBs and their corresponding GP GBs have almost identical strengths for most of the simulated results. Notable differences between CNT and GP GBs were only found at misorientations near 0 and 30° in armchair GBs. These strength differences were attributed to the crack stabilization and structural reconstruction in CNT GBs.
{"title":"Tensile strength of a transverse grain boundary in a single-walled carbon nanotube","authors":"Yaoshu Xie, Kiyou Shibata, Teruyasu Mizoguchi","doi":"10.2109/jcersj2.23062","DOIUrl":"https://doi.org/10.2109/jcersj2.23062","url":null,"abstract":"Adding carbon nanotubes (CNTs) into ceramics is an important way to promote toughness. Crystalline defects existing in materials play a significant role in affecting both their mechanical and functional performances because they bring symmetry breaking of the periodic lattice structures. For CNTs existing in real ceramic materials, which almost appear as polycrystalline forms, the most notable defects are the grain boundaries (GBs) which consist of defect cores of dislocations. It is of engineering importance to investigate the effects of these defect cores of GBs on the strength of the polycrystalline CNTs to promote the composites’ performances. The variety of grain orientations of the polycrystalline CNTs allows the GBs to have various misorientations and different arrangements of the defect cores of dislocations at the GBs, which causes disparity in the stress fields near the GBs under an external stress condition, thus making distinguishable effects on the strength. While effective rules have been established for graphene (GP) GBs to predict the tensile strengths of GP GBs with different misorientations, the effects of misorientation and curvature on the strength of CNT GBs have yet to be reported. This work studied these effects by molecular dynamics (MD) simulation. The results illustrate that the misorientation and temperature have much more significant effects than the curvature on the strength of CNT GBs, and verified a consistent tendency of the misorientation-strength relationship of the CNT GBs with the corresponding GP GBs. The CNT GBs and their corresponding GP GBs have almost identical strengths for most of the simulated results. Notable differences between CNT and GP GBs were only found at misorientations near 0 and 30° in armchair GBs. These strength differences were attributed to the crack stabilization and structural reconstruction in CNT GBs.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372976","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 : 2023-10-01DOI: 10.2109/jcersj2.131.a10-1
{"title":"Call for a Guest Editor for a Special Issue","authors":"","doi":"10.2109/jcersj2.131.a10-1","DOIUrl":"https://doi.org/10.2109/jcersj2.131.a10-1","url":null,"abstract":"","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372981","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}
Takuya Sasaki, Ryota Asaka, Ken Niwa, Nico Alexander Gaida, Masashi Hasegawa
Ga- and Gd-substituted garnet-type Y3Al5O12:Mn4+ phosphors, Y3(Al1−xGax)5O12:Mn4+ and (Y1−yGdy)3Al5O12:Mn4+, were synthesized by a conventional solid-state reaction to elucidate the relationship between the emission and the local structure of the activator in the host material. Completely substituted Y3(Al1−xGax)5O12 and ∼80 % substituted (Y1−yGdy)3Al5O12 (y ≤ ∼0.8) solid solutions have been produced. The lattice parameters of the garnet-type solid solutions increased linearly with the substitution of Ga and Gd for Al and Y sites, respectively. The emission peak attributed to the Mn4+ luminescence center of their garnet-type solid solutions shifted toward a longer wavelength side by substituting Ga and Gd. The emission peak wavelength of the Mn4+-activated garnet-type solid solutions increased almost linearly with increasing the average bond length between the cation and anion in the dodecahedral sites. The dodecahedral site in the garnet structure is edge-sharing with the octahedral site where Mn4+ exists. These results indicate that the emission wavelength can be controlled by changing the local structure around Mn4+ due to the cation substitution of coordination polyhedra neighboring Mn4+ coordination polyhedra.
{"title":"Synthesis of garnet-type Mn<sup>4+</sup>-activated Y<sub>3</sub>(Al,Ga)<sub>5</sub>O<sub>12</sub> and (Y,Gd)<sub>3</sub>Al<sub>5</sub>O<sub>12</sub> phosphors with controlled emission by cation substitution","authors":"Takuya Sasaki, Ryota Asaka, Ken Niwa, Nico Alexander Gaida, Masashi Hasegawa","doi":"10.2109/jcersj2.23063","DOIUrl":"https://doi.org/10.2109/jcersj2.23063","url":null,"abstract":"Ga- and Gd-substituted garnet-type Y3Al5O12:Mn4+ phosphors, Y3(Al1−xGax)5O12:Mn4+ and (Y1−yGdy)3Al5O12:Mn4+, were synthesized by a conventional solid-state reaction to elucidate the relationship between the emission and the local structure of the activator in the host material. Completely substituted Y3(Al1−xGax)5O12 and ∼80 % substituted (Y1−yGdy)3Al5O12 (y ≤ ∼0.8) solid solutions have been produced. The lattice parameters of the garnet-type solid solutions increased linearly with the substitution of Ga and Gd for Al and Y sites, respectively. The emission peak attributed to the Mn4+ luminescence center of their garnet-type solid solutions shifted toward a longer wavelength side by substituting Ga and Gd. The emission peak wavelength of the Mn4+-activated garnet-type solid solutions increased almost linearly with increasing the average bond length between the cation and anion in the dodecahedral sites. The dodecahedral site in the garnet structure is edge-sharing with the octahedral site where Mn4+ exists. These results indicate that the emission wavelength can be controlled by changing the local structure around Mn4+ due to the cation substitution of coordination polyhedra neighboring Mn4+ coordination polyhedra.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372984","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}
Eri Fukushina, Tatsuaki Sakamoto, Hiromichi Takebe
Two types of glass particles were immersed in simulated body fluid (SBF) at 37 °C. Silicate glass 45S5 with a trademark name “Bioglass” only formed hydroxyapatite (HAp) near the particle surface, leaving a large amount of silica gel in the interior. The second glass type was borosilicate glass with a composition of the 45S5 glass in which a major part of SiO2 was replaced with B2O3; in the samples from it, glass was completely replaced with HAp inside the particles. We used Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, field-emission scanning electron microscopy, and transmission electron microscopy (TEM) to characterize the microscopic structure of samples. When the 45S5 glass was immersed in SBF, the PO43−(Q0) in glass quickly formed amorphous calcium phosphate (ACP), a precursor of HAp. Ca2+ preferentially coordinated with PO43−(Q0) forming ACP [Ca2+–PO43−(Q0)], which is considered stable, where the notation Qn represents the number (n) of the bridging oxygen atoms per PO4 tetrahedron. The TEM results showed that the columnar crystals of HAp grew along the c-axis. In the borosilicate glass, the reaction is thought to progress to the inside through ion transport into the space where B2O3 was eluted.
{"title":"Microstructural investigation of hydroxyapatite formation in bioactive borosilicate glass","authors":"Eri Fukushina, Tatsuaki Sakamoto, Hiromichi Takebe","doi":"10.2109/jcersj2.23113","DOIUrl":"https://doi.org/10.2109/jcersj2.23113","url":null,"abstract":"Two types of glass particles were immersed in simulated body fluid (SBF) at 37 °C. Silicate glass 45S5 with a trademark name “Bioglass” only formed hydroxyapatite (HAp) near the particle surface, leaving a large amount of silica gel in the interior. The second glass type was borosilicate glass with a composition of the 45S5 glass in which a major part of SiO2 was replaced with B2O3; in the samples from it, glass was completely replaced with HAp inside the particles. We used Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, field-emission scanning electron microscopy, and transmission electron microscopy (TEM) to characterize the microscopic structure of samples. When the 45S5 glass was immersed in SBF, the PO43−(Q0) in glass quickly formed amorphous calcium phosphate (ACP), a precursor of HAp. Ca2+ preferentially coordinated with PO43−(Q0) forming ACP [Ca2+–PO43−(Q0)], which is considered stable, where the notation Qn represents the number (n) of the bridging oxygen atoms per PO4 tetrahedron. The TEM results showed that the columnar crystals of HAp grew along the c-axis. In the borosilicate glass, the reaction is thought to progress to the inside through ion transport into the space where B2O3 was eluted.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372987","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}
Oxides containing unusually high-valence transition-metal ions often exhibit charge transitions to relieve the electronic instabilities. A-site-ordered quadruple perovskites LnCu3Fe4O12 with the unusually high-valence Fe3.75+, which are synthesized under high-pressure conditions, show intermetallic-charge-transfer transitions. In this review article, novel thermo-related functional properties induced by the charge transitions in LnCu3Fe4O12 are highlighted. A large negative-thermal-expansion behavior was observed at the intermetallic-charge-transfer transition temperature. The negative-thermal-expansion property is primarily caused by the size effect of constituent ions by the charge changes. The property is useful for developing materials to compensate the normal positive thermal expansion. Significant latent heat was also found to be provided by the intermetallic-charge-transfer transition in LnCu3Fe4O12. The large latent heat is considered to be related with unusual first-order magnetic entropy change induced by the charge transition. The large entropy change can be utilized for thermal control through a caloric effect, which can make effective energy systems for thermal energy storage and refrigeration.
{"title":"Novel functional properties of charge-transition oxides synthesized under high pressure","authors":"Yuichi Shimakawa","doi":"10.2109/jcersj2.23115","DOIUrl":"https://doi.org/10.2109/jcersj2.23115","url":null,"abstract":"Oxides containing unusually high-valence transition-metal ions often exhibit charge transitions to relieve the electronic instabilities. A-site-ordered quadruple perovskites LnCu3Fe4O12 with the unusually high-valence Fe3.75+, which are synthesized under high-pressure conditions, show intermetallic-charge-transfer transitions. In this review article, novel thermo-related functional properties induced by the charge transitions in LnCu3Fe4O12 are highlighted. A large negative-thermal-expansion behavior was observed at the intermetallic-charge-transfer transition temperature. The negative-thermal-expansion property is primarily caused by the size effect of constituent ions by the charge changes. The property is useful for developing materials to compensate the normal positive thermal expansion. Significant latent heat was also found to be provided by the intermetallic-charge-transfer transition in LnCu3Fe4O12. The large latent heat is considered to be related with unusual first-order magnetic entropy change induced by the charge transition. The large entropy change can be utilized for thermal control through a caloric effect, which can make effective energy systems for thermal energy storage and refrigeration.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372990","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}
Octacalcium phosphate (OCP) has a layered structure and various carboxylate ions can be incorporated into its structure as interlayer ions. In recent studies, aromatic carboxylate ions have been incorporated into OCP to impart fluorescence properties. In such fluorescent OCP materials, the incorporated carboxylate ions can be regarded as ‘crystal defect cores’. Although fluorescent OCPs with incorporated benzenedicarboxylate ions have been reported, the synthesis and fluorescence of OCPs with incorporated pyridinedicarboxlate ions have not yet been investigated. In this study, our aim was to synthesise OCP with incorporated 2,5-pyridinedicarboxylate ions and evaluate its fluorescence behaviour. Samples were synthesised by reacting calcium carbonate and phosphoric acid in 2,5-pyridinedicarboxylic acid solution. When the 2,5-pyridinedicarboxylic acid concentration in the solution was low, plate-shaped crystals of OCP with incorporated 2,5-pyridinedicarboxylate ions were formed. As the 2,5-pyridinedicarboxylic acid concentration increased, OCP formation was suppressed, and a poorly soluble salt composed of calcium and 2,5-pyridinedicarboxylate ions was formed in its place. The (100) interplanar spacing of OCP was increased from 1.87 to 2.26 nm by the incorporation of 2,5-pyridinedicarboxylate ions as interlayer ions. The incorporation of 2,5-pyridinedicarboxylate ions was confirmed by Fourier-transform infrared spectroscopy. OCP with incorporated 2,5-pyridinedicarboxylate ions exhibited fluorescence with an emission wavelength of 430 nm upon excitation at 320 nm. The results of this study should prove useful for the design and development of fluorescent OCP materials.
{"title":"Synthesis and fluorescence properties of octacalcium phosphate with incorporated pyridinedicarboxylate ions","authors":"Taishi Yokoi, Masahiro Watanabe, Yuejun Wang, Tomoyo Goto, Tohru Sekino, Masaya Shimabukuro, Masakazu Kawashita","doi":"10.2109/jcersj2.23027","DOIUrl":"https://doi.org/10.2109/jcersj2.23027","url":null,"abstract":"Octacalcium phosphate (OCP) has a layered structure and various carboxylate ions can be incorporated into its structure as interlayer ions. In recent studies, aromatic carboxylate ions have been incorporated into OCP to impart fluorescence properties. In such fluorescent OCP materials, the incorporated carboxylate ions can be regarded as ‘crystal defect cores’. Although fluorescent OCPs with incorporated benzenedicarboxylate ions have been reported, the synthesis and fluorescence of OCPs with incorporated pyridinedicarboxlate ions have not yet been investigated. In this study, our aim was to synthesise OCP with incorporated 2,5-pyridinedicarboxylate ions and evaluate its fluorescence behaviour. Samples were synthesised by reacting calcium carbonate and phosphoric acid in 2,5-pyridinedicarboxylic acid solution. When the 2,5-pyridinedicarboxylic acid concentration in the solution was low, plate-shaped crystals of OCP with incorporated 2,5-pyridinedicarboxylate ions were formed. As the 2,5-pyridinedicarboxylic acid concentration increased, OCP formation was suppressed, and a poorly soluble salt composed of calcium and 2,5-pyridinedicarboxylate ions was formed in its place. The (100) interplanar spacing of OCP was increased from 1.87 to 2.26 nm by the incorporation of 2,5-pyridinedicarboxylate ions as interlayer ions. The incorporation of 2,5-pyridinedicarboxylate ions was confirmed by Fourier-transform infrared spectroscopy. OCP with incorporated 2,5-pyridinedicarboxylate ions exhibited fluorescence with an emission wavelength of 430 nm upon excitation at 320 nm. The results of this study should prove useful for the design and development of fluorescent OCP materials.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136081117","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}
Machine learning potentials (MLPs) are attracting much attention as powerful tools to accurately and efficiently perform atomistic simulations and crystal structure predictions. In this study, we develop a polynomial MLP for the Al–Cu system applicable to the robust global structure search and metastable structure enumeration. We then apply a combination of a global optimization method and the polynomial MLP to the Al–Cu alloy system. As a result of approximately 1010 times energy computations, the globally-stable and metastable structures are enumerated in the Al–Cu system.
{"title":"Efficient global crystal structure prediction using polynomial machine learning potential in the binary Al–Cu alloy system","authors":"Hayato Wakai, Atsuto Seko, Isao Tanaka","doi":"10.2109/jcersj2.23053","DOIUrl":"https://doi.org/10.2109/jcersj2.23053","url":null,"abstract":"Machine learning potentials (MLPs) are attracting much attention as powerful tools to accurately and efficiently perform atomistic simulations and crystal structure predictions. In this study, we develop a polynomial MLP for the Al–Cu system applicable to the robust global structure search and metastable structure enumeration. We then apply a combination of a global optimization method and the polynomial MLP to the Al–Cu alloy system. As a result of approximately 1010 times energy computations, the globally-stable and metastable structures are enumerated in the Al–Cu system.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372639","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}
Scanning tunneling microscopy imaging of Fe deposited SrTiO3(100)-(√13 × √13)-R33.7° surface is presented. Low-energy electron diffraction patterns showed that the surface reconstruction remained after Fe deposition at room temperature. Fe deposition generated defects, including oxygen vacancies, on the SrTiO3(100)-(√13 × √13)-R33.7° surface. These defects have a periodicity with the c(√13 × √13) symmetry. Scanning tunneling spectroscopy demonstrated the formation of two types of defects: one had the same density of state with defects on the bare SrTiO3(100)-(√13 × √13)-R33.7° surface, and the other had a narrow band gap structure. These results are attributed the formation of a two-dimensional hole gas at the FeOx/SrTiO3(100) interface.
{"title":"Scanning tunneling microscopy observation of Fe deposited SrTiO<sub>3</sub>(100)-(√13 × √13)-R33.7° surface","authors":"Daiki Katsube, Naoki Origuchi, Motoyasu Maeda, Masayuki Abe","doi":"10.2109/jcersj2.23068","DOIUrl":"https://doi.org/10.2109/jcersj2.23068","url":null,"abstract":"Scanning tunneling microscopy imaging of Fe deposited SrTiO3(100)-(√13 × √13)-R33.7° surface is presented. Low-energy electron diffraction patterns showed that the surface reconstruction remained after Fe deposition at room temperature. Fe deposition generated defects, including oxygen vacancies, on the SrTiO3(100)-(√13 × √13)-R33.7° surface. These defects have a periodicity with the c(√13 × √13) symmetry. Scanning tunneling spectroscopy demonstrated the formation of two types of defects: one had the same density of state with defects on the bare SrTiO3(100)-(√13 × √13)-R33.7° surface, and the other had a narrow band gap structure. These results are attributed the formation of a two-dimensional hole gas at the FeOx/SrTiO3(100) interface.","PeriodicalId":17246,"journal":{"name":"Journal of the Ceramic Society of Japan","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372810","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}
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