Coherently moving flocks of beasts, birds and bacteria are an example of polar nematic liquid‐crystalline order in the living world. The highly ordered local structures seen in the configurations of the biopolymeric filaments, energized by molecular motors, in the cytoskeleton of a living cell are another example; and chemically or mechanically agitated orientable particles such as catalytic colloidal rods or monolayers of macroscopic bits of wire are a third. There has been a great deal of progress in understanding the states, phase transitions, and fluctuations of these nonequilibrium systems, known broadly as Active Matter, and the methods used are a nice generalization of the hydrodynamic approach to liquid crystals. Among the interesting results that have emerged are some curious instabilities in bulk as well as thin‐film geometries; the peculiar kinetics of domain growth of active nematics; anomalies in the dynamics of a stiff filament in an active medium, and the twisted instabilities of chiral act...
{"title":"Active Matter: Liquid‐Crystal Hydrodynamics With a Difference","authors":"S. Ramaswamy","doi":"10.1063/1.3605730","DOIUrl":"https://doi.org/10.1063/1.3605730","url":null,"abstract":"Coherently moving flocks of beasts, birds and bacteria are an example of polar nematic liquid‐crystalline order in the living world. The highly ordered local structures seen in the configurations of the biopolymeric filaments, energized by molecular motors, in the cytoskeleton of a living cell are another example; and chemically or mechanically agitated orientable particles such as catalytic colloidal rods or monolayers of macroscopic bits of wire are a third. There has been a great deal of progress in understanding the states, phase transitions, and fluctuations of these nonequilibrium systems, known broadly as Active Matter, and the methods used are a nice generalization of the hydrodynamic approach to liquid crystals. Among the interesting results that have emerged are some curious instabilities in bulk as well as thin‐film geometries; the peculiar kinetics of domain growth of active nematics; anomalies in the dynamics of a stiff filament in an active medium, and the twisted instabilities of chiral act...","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"65 1","pages":"27-27"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85029478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Positron lifetime technique was used to determine the size distribution of free volume holes in some natural polymers–animal hair, feather, cotton and silk. The effect of fiber swelling on the nature of size distribution was also monitored. The obtained positron lifetime spectra were analyzed by using the computer program CONTIN (PALS‐2). Significant differences in the size distribution were observed for these biological polymers (and even among the different animal hair types), possibly due to the structural differences, which have not been investigated hitherto.
{"title":"Free Volume Size Distribution in Some Natural Polymers","authors":"M. N. Chandrashekara, C. Ranganathaiah","doi":"10.1063/1.3605819","DOIUrl":"https://doi.org/10.1063/1.3605819","url":null,"abstract":"Positron lifetime technique was used to determine the size distribution of free volume holes in some natural polymers–animal hair, feather, cotton and silk. The effect of fiber swelling on the nature of size distribution was also monitored. The obtained positron lifetime spectra were analyzed by using the computer program CONTIN (PALS‐2). Significant differences in the size distribution were observed for these biological polymers (and even among the different animal hair types), possibly due to the structural differences, which have not been investigated hitherto.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"85 1","pages":"228-229"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76331626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compacts of silica micro‐spheres prepared for different times at sintering temperatures of 640 °C and 740 °C have been studied by Ultra Small‐Angle Neutron Scattering (USANS) and Scanning Electron Microscopy (SEM). Stress versus strain measurements display several breakage points related to a range of nearest neighbour coordination around each microsphere.
{"title":"Ultra Small‐Angle Neutron Scattering Study of Porous Glass","authors":"Reshma R. Desai, J. Desa, D. Sen, S. Mazumder","doi":"10.1063/1.3605965","DOIUrl":"https://doi.org/10.1063/1.3605965","url":null,"abstract":"Compacts of silica micro‐spheres prepared for different times at sintering temperatures of 640 °C and 740 °C have been studied by Ultra Small‐Angle Neutron Scattering (USANS) and Scanning Electron Microscopy (SEM). Stress versus strain measurements display several breakage points related to a range of nearest neighbour coordination around each microsphere.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"1 1","pages":"527-528"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88638522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
UV‐visible absorption studies and refractive index measurements at wavelengths of 458, 492.2 , 499, 546, 589, 632.8 , 659.2, 670.2 nanometers were taken of Rhodamine 6G doped Poly(carbonate) films. The absorption studies on the PC‐ Rhodamine composites showed blue shifts for samples at concentrations of 0.01,0.05,0.1,0.5 % of Rhodamine 6G suggesting the formation of nanoparticles. The optical dispersion of the poly(carbonate) was satisfactorily given by the Schott equation.
{"title":"Blue Shifts and Refractive Index of Rhodamine 6G doped Polycarbonate","authors":"K. Das, Sheetal Mehta, Rashmi Singh","doi":"10.1063/1.3606353","DOIUrl":"https://doi.org/10.1063/1.3606353","url":null,"abstract":"UV‐visible absorption studies and refractive index measurements at wavelengths of 458, 492.2 , 499, 546, 589, 632.8 , 659.2, 670.2 nanometers were taken of Rhodamine 6G doped Poly(carbonate) films. The absorption studies on the PC‐ Rhodamine composites showed blue shifts for samples at concentrations of 0.01,0.05,0.1,0.5 % of Rhodamine 6G suggesting the formation of nanoparticles. The optical dispersion of the poly(carbonate) was satisfactorily given by the Schott equation.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"139 1","pages":"1317-1318"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89026697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zinc Oxide (ZnO) based heterojunction has been fabricated by spin coating p‐type polymer Polyaniline on n‐type ZnO film. The ZnO film has been deposited by ultrasonically assisted chemical vapor deposition method on patterned Indium Tin Oxide coated glass substrate. Aluminum was deposited on top of the Polyaniline film by thermal evaporation. The current‐voltage (I‐V) characteristic of Polyaniline/ZnO shows diode like behavior. The I‐V characteristic was examined in the frame work of thermionic emission model. The ideality factor and barrier height were obtained as ∼4.0 and ∼0.68 eV respectively.
{"title":"Polyaniline/ZnO Heterojunction","authors":"B. Sharma, Babu Banothu, N. Khare","doi":"10.1063/1.3606057","DOIUrl":"https://doi.org/10.1063/1.3606057","url":null,"abstract":"Zinc Oxide (ZnO) based heterojunction has been fabricated by spin coating p‐type polymer Polyaniline on n‐type ZnO film. The ZnO film has been deposited by ultrasonically assisted chemical vapor deposition method on patterned Indium Tin Oxide coated glass substrate. Aluminum was deposited on top of the Polyaniline film by thermal evaporation. The current‐voltage (I‐V) characteristic of Polyaniline/ZnO shows diode like behavior. The I‐V characteristic was examined in the frame work of thermionic emission model. The ideality factor and barrier height were obtained as ∼4.0 and ∼0.68 eV respectively.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"11 1","pages":"713-714"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88737150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Sangeetha, A. Thamizhavel, S. Basu, S. Ramakrishnan, D. Pal
We report here transport and magnetic properties of the R2Ir3Sn5 (R = La, Ce, Pr, Nd) system. R2Ir3Sn5 (R = Ce to Nd) crystallizes in orthorhombic structure (Cmc21) while La2Ir3Sn5 forms in orthorhombic U2Co3Si5 (Ibam) structure. Ce2Ir3Sn5 depicts Kondo behavior (Kondo temperature, TK = 271 K) accompanied with an antiferromagnetic ordering at 3.5 K. Studies on Pr2Ir3Sn5 and Nd2Ir3Sn5 indicate magnetic ordering below 5 K.
本文报道了R2Ir3Sn5 (R = La, Ce, Pr, Nd)体系的输运和磁性能。R2Ir3Sn5 (R = Ce to Nd)结晶为正交晶型(Cmc21)， La2Ir3Sn5结晶为正交晶型(Ibam)。Ce2Ir3Sn5具有近藤行为(近藤温度，TK = 271 K)，并伴有3.5 K的反铁磁有序。Pr2Ir3Sn5和Nd2Ir3Sn5的研究表明，磁性有序度低于5k。
{"title":"Transport and Magnetic Properties of R2Ir3Sn5 (R = La, Ce, Pr, and Nd) System","authors":"N. Sangeetha, A. Thamizhavel, S. Basu, S. Ramakrishnan, D. Pal","doi":"10.1063/1.3606303","DOIUrl":"https://doi.org/10.1063/1.3606303","url":null,"abstract":"We report here transport and magnetic properties of the R2Ir3Sn5 (R = La, Ce, Pr, Nd) system. R2Ir3Sn5 (R = Ce to Nd) crystallizes in orthorhombic structure (Cmc21) while La2Ir3Sn5 forms in orthorhombic U2Co3Si5 (Ibam) structure. Ce2Ir3Sn5 depicts Kondo behavior (Kondo temperature, TK = 271 K) accompanied with an antiferromagnetic ordering at 3.5 K. Studies on Pr2Ir3Sn5 and Nd2Ir3Sn5 indicate magnetic ordering below 5 K.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"3 1","pages":"1215-1216"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89865355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ZnO nanostructures of different morphology (Rods, spindles, stars, buds) were successfully synthesized by co‐precipitation method. The prepared ZnO nanostructures were systematically characterized by X‐ray diffraction, Scanning electron microscopy (SEM). XRD results show the prepared nanostructures were in the hexagonal wurtzite structure. The photocatalytic degradation of methylene blue (MB) in aqueous solution under UV‐irradiation was investigated with different ZnO nanostructures. The photocatalytic experiments reveal that spindle like nanostructures showed fast photocatalytic activity compared to the other rods, stars and buds like nanostructures.
{"title":"Morphology Dependent Photocatalytic Properties of ZnO Nanostructures","authors":"K. Ranjith, R. Kumar","doi":"10.1063/1.3605919","DOIUrl":"https://doi.org/10.1063/1.3605919","url":null,"abstract":"ZnO nanostructures of different morphology (Rods, spindles, stars, buds) were successfully synthesized by co‐precipitation method. The prepared ZnO nanostructures were systematically characterized by X‐ray diffraction, Scanning electron microscopy (SEM). XRD results show the prepared nanostructures were in the hexagonal wurtzite structure. The photocatalytic degradation of methylene blue (MB) in aqueous solution under UV‐irradiation was investigated with different ZnO nanostructures. The photocatalytic experiments reveal that spindle like nanostructures showed fast photocatalytic activity compared to the other rods, stars and buds like nanostructures.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"112 1","pages":"431-432"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79547353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The geometrically frustrated pyrochlores Gd2Hf2O7 (GdH) and Gd2Zr2O7 (GdZ) are easy planar anisotropic systems in which considerable single‐ion crystal‐field anisotropies of D3d symmetry are found in the ground multiplet 8S7/2 due to admixture of higher Russell‐Saunders terms. The 8S7/2 splits into 4 doublets with total CF splitting 9.9 K in GdH and 9.4 K in GdZ. The magnetic specific heat Cmag follows a conventional T3 behavior in GdH and an unconventional T4.6 behavior in GdZ down to 0.4 K.
{"title":"Study on the low‐temperature properties of pyrochlores Gd2Hf2O7 and Gd2Zr2O7, using crystal‐field theory","authors":"A. A. Biswas, Y. Jana","doi":"10.1063/1.3606256","DOIUrl":"https://doi.org/10.1063/1.3606256","url":null,"abstract":"The geometrically frustrated pyrochlores Gd2Hf2O7 (GdH) and Gd2Zr2O7 (GdZ) are easy planar anisotropic systems in which considerable single‐ion crystal‐field anisotropies of D3d symmetry are found in the ground multiplet 8S7/2 due to admixture of higher Russell‐Saunders terms. The 8S7/2 splits into 4 doublets with total CF splitting 9.9 K in GdH and 9.4 K in GdZ. The magnetic specific heat Cmag follows a conventional T3 behavior in GdH and an unconventional T4.6 behavior in GdZ down to 0.4 K.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"27 1","pages":"1121-1122"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83195468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Ramgir, S. Ganapathi, M. Kaur, S. Mishra, N. Datta, D. K. Aswal, S. Gupta, J. Yakhmi
Gas sensing properties of pure and Au incorporated WO3 thin films towards H2S and Cl2 have been investigated. The sensor films were able to detect H2S and Cl2 selectively at an operating temperature of 150 and 200 °C, respectively. Effect of gas concentration and Au loading have been investigated and correlated with the observed sensitivity values. Pure WO3 films exhibited better sensing characteristics towards H2S (S = 17, 10 ppm, 150 °C) while sensor film containing Au thickness of 21.6 nm exhibited a maximum sensitivity towards Cl2 (S = 89, 10 ppm, 200 °C)..
研究了纯WO3薄膜和Au掺杂WO3薄膜对H2S和Cl2的气敏性能。传感器膜能够在150°C和200°C的工作温度下选择性地检测H2S和Cl2。研究了气体浓度和载金量的影响，并将其与观测到的灵敏度值进行了关联。纯WO3薄膜对H2S (S = 17,10 ppm, 150°C)表现出更好的传感特性，而含Au厚度为21.6 nm的传感器薄膜对Cl2 (S = 89, 10 ppm, 200°C)表现出最大的灵敏度。
{"title":"Improved H2S and Cl2 Sensing Characteristics of Pure and Au Incorporated WO3 Thin Films","authors":"N. Ramgir, S. Ganapathi, M. Kaur, S. Mishra, N. Datta, D. K. Aswal, S. Gupta, J. Yakhmi","doi":"10.1063/1.3606040","DOIUrl":"https://doi.org/10.1063/1.3606040","url":null,"abstract":"Gas sensing properties of pure and Au incorporated WO3 thin films towards H2S and Cl2 have been investigated. The sensor films were able to detect H2S and Cl2 selectively at an operating temperature of 150 and 200 °C, respectively. Effect of gas concentration and Au loading have been investigated and correlated with the observed sensitivity values. Pure WO3 films exhibited better sensing characteristics towards H2S (S = 17, 10 ppm, 150 °C) while sensor film containing Au thickness of 21.6 nm exhibited a maximum sensitivity towards Cl2 (S = 89, 10 ppm, 200 °C)..","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"320 1","pages":"679-680"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76461508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Mistry, B. V. Mistry, U. Trivedi, R. Pinto, U. Joshi
Transparent all oxide p‐n junction thin film diode nanostructures consisting of n‐type ZnO:Al and p‐type NiO was fabricated by pulsed laser deposition onto c‐sapphire substrate. Details of device fabrication will be presented. Combined GIXRD and AFM results confirm phase pure, mono‐dispersed 30 nm ZnO:Al and NiO:Li nanocrystallites with RMS roughness of the films were controlled to be that of NiO unit cell parameter. Better than 70% optical transparency is achieved across the 180 nm thick p‐n junction. The optical band gap across the junction was found to decrease as compare to the ITO and NiO. The current voltage (I‐V) characteristics show excellent rectifying characteristics with dynamic transfer resistance of the order of 104 in the forward bias condition. The observed rectifying I‐V properties were reproducible for several voltage sweeping cycles. The optical and electrical properties of oxide transparent diode offer variety of applications in oxide electronics and photonics.
{"title":"Fabrication and Electrical Properties of Transparent n‐ZnO:Al‐p‐NiO:Li Junction","authors":"J. Mistry, B. V. Mistry, U. Trivedi, R. Pinto, U. Joshi","doi":"10.1063/1.3606063","DOIUrl":"https://doi.org/10.1063/1.3606063","url":null,"abstract":"Transparent all oxide p‐n junction thin film diode nanostructures consisting of n‐type ZnO:Al and p‐type NiO was fabricated by pulsed laser deposition onto c‐sapphire substrate. Details of device fabrication will be presented. Combined GIXRD and AFM results confirm phase pure, mono‐dispersed 30 nm ZnO:Al and NiO:Li nanocrystallites with RMS roughness of the films were controlled to be that of NiO unit cell parameter. Better than 70% optical transparency is achieved across the 180 nm thick p‐n junction. The optical band gap across the junction was found to decrease as compare to the ITO and NiO. The current voltage (I‐V) characteristics show excellent rectifying characteristics with dynamic transfer resistance of the order of 104 in the forward bias condition. The observed rectifying I‐V properties were reproducible for several voltage sweeping cycles. The optical and electrical properties of oxide transparent diode offer variety of applications in oxide electronics and photonics.","PeriodicalId":16850,"journal":{"name":"Journal of Physics C: Solid State Physics","volume":"8 1","pages":"725-726"},"PeriodicalIF":0.0,"publicationDate":"2011-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83655013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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