scholarly journals Температурная зависимость проводимости нитевидных кристаллов теллура

2021 ◽  
Vol 55 (6) ◽  
pp. 493
Author(s):  
М.Р. Рабаданов ◽  
А.А. Степуренко ◽  
А.Э. Гумметов ◽  
А.М. Исмаилов
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Comparative Analysis ◽  
Single Crystal ◽  
Diffuse Scattering ◽  
Epitaxial Film ◽  
Thermal Excitation ◽  
Increasing Temperature ◽  
Classical Size ◽  
Scanning Electron

In the temperature range 77−273K, a comparative analysis of the electrical conductivity of a whisker, an epitaxial film, and a single crystal of tellurium was undertaken. The electrical conductivity of the film and the single crystal increased monotonically up to 200K, then began to rise steeply, corresponding to thermal excitation of intrinsic carriers. The electrical conductivity of whiskers decreased with increasing temperature to 230K, after which it began to increase more gradually. It is assumed that in the case of tellurium whiskers, the classical size effect took place: the decrease in electrical conductivity was due to diffuse scattering of carriers by the lateral surface of the tellurium crystal and was intensified with increasing temperature. The uneven, tightly-convoluted surface of the samples was shown in images produced in a scanning electron microscope in the nanometer range.

Mounting an individual submicrometer sized single crystal

1996 ◽  
Vol 211 (6) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
High Vacuum ◽  
Nanometer Resolution ◽  
Micro Manipulator ◽  
Scanning Electron

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1

Microstructures of Low Angle Boundaries of the Second Generation Single Crystal Superalloy DD6

2011 ◽  
Vol 284-286 ◽  
pp. 1584-1587
Author(s):  
Zhen Xue Shi ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Single Crystal ◽  
Second Generation ◽  
Three Dimensional ◽  
Single Crystal Superalloy ◽  
Transition Electron ◽  
Scanning Electron

The specimens of low angle boundaries were machined from the second generation single crystal superalloy DD6 blades. The microstructures of low angle boundaries (LAB) were investigated from three scales of dendrite, γ′ phase and atom with optical microscopy (OM), scanning electron microscope (SEM), transition electron microscope (TEM) and high resolution transmission electrion microscopy (HREM). The results showed that on the dendrite scale LAB is interdendrite district formed by three dimensional curved face between the adjacent dendrites. On the γ′ phase scale LAB is composed by a thin layer γ phase and its bilateral imperfect cube γ′ phase. On the atom scale LAB is made up of dislocations within several atom thickness.

scholarly journals Blended PVA/PVP Electro spun nanofibers for Coating Application

2021 ◽  
Vol 2114 (1) ◽  
pp. 012031
Author(s):  
R Mohammed ◽  
H Jawad ◽  
A. Al-Zubiedy
Keyword(s):  
Electrical Conductivity ◽  
Contact Angle ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Weight Ratio ◽  
Polymeric Materials ◽  
Vinyl Pyrrolidone ◽  
Pumping Rate ◽  
Coating Application ◽  
Scanning Electron

Abstract The use of polymeric blended nanofibres is one of the recent applications in the food and liquid packaging. The current research aims to prepare the nanofibers coatings from the blend of polymeric materials via the electro spinning technique 0.08 weight ratio concentration of polyvinyl alcohol (PVA) dissolved in water, as well as, (0.2 weight ratio concentration ) of poly vinyl pyrrolidone (PVP) were used to obtain different volume proportions of (PVA:PVP) solutions include (100:0, 80:20,70:30, 50:50, 20:80, and 0:100). The electro spinning system was organized with pumping conditions (20 kV for the applied voltage, 20 cm pumping distance, 1ml/hr pumping rate) and a needle diameter with 0.4mm diameter. The properties of the polymeric solutions involve (viscosity, surface tension, and electrical conductivity of the liquid) were examined. A scanning electron microscope technique was used to study the surface properties of the prepared films, and the contact angle via the contact angle analyzer was examined. The results of a scanning electron microscope proved that the diameter of the nano fibers increases with increasing the concentration and viscosity of solutions and decreasing its electrical conductivity. Also, the results of the contact angle analyzer showed an increase the hydrophilic property via increasing percentage of polyvinylpyrrolidone.

scholarly journals Karakterisasi Mineral Magnetik Sedimen Sungai Citarum Hilir Melalui Analisa Sifat Magnetik, Mineralogi serta Morfologi Magnetik

POSITRON ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 52
Author(s):  
Kartika Hajar Kirana ◽  
Mechdi Ghazali ◽  
Luh Ayu Eka Safitri Septiana ◽  
Dini Fitriani ◽  
Eleonora Agustine ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Total Dissolve Solid ◽  
X Ray ◽  
Scanning Electron

Sungai Citarum merupakan sungai utama yang ada di Provinsi Jawa Barat yang sangat penting bagi kehidupan sosial dan ekonomi. Di bagian hilir, Sungai Citarum ini banyak melewati daerah pemukiman padat penduduk, daerah industri, dan bahkan pesawahan. Oleh karena itu, perlu kajian mengenai kondisi Sungai Citarum salah satunya dengan mengidentifikasi parameter electrical conductivity (EC), total dissolve solid (TDS), pH dan suhu serta karakteristik mineral magnetik pada sedimen melalui analisis sifat magnetik, mineralogi dan morfologi magnetiknya. Pengukuran parameter EC, TDS, pH dan suhu dilakukan secara in situ pada sampel air Sungai Citarum, pengukuran sifat magnetik dilakukan pada sampel sedimen yang telah dipreprasi, sedangkan pengukuran mineralogi dan morfologi dilakukan pada sampel sedimen yang telah diekstraksi. Sifat magnetik sedimen diketahui dari nilai suseptibilitas magnetik dual frekuensi yang diukur menggunakan Bartington Magnetik Susceptibilitymeter, sedangkan mineralogi dan morfologi magnetik diketahui berdasarkan hasil pengukuran scanning electron microscope–energy disperdsive x-ray (SEM-EDS) dan x-ray diffractometer (XRD). Hasil pengukuran secara in situ pada sampel air menunjukkan bahwa rentang nilai EC, TDS, pH dan suhu berturut-turut adalah (200–4120) mS/cm, (100–2060) ppt, 7,34–9,22, dan (26,8–32,6) oC. Sedangkan, hasil pengukuran sifat magnetik menunjukkan bahwa sampel sedimen Sungai Citarum bagian hilir memiliki nilai suseptibilitas magnetik frekuensi rendah (cLF) dengan rentang (65,00–173,80) x 10-8 m3/kg, sedangkan rentang nilai suseptibilitas magnetik frekuensi tinggi (cHF) adalah (64,90–165,70) x 10-8 m3/kg. Dari kedua pengukuran cLF dan cHF diperoleh rentang nilai cFD (%) sebesar 0,15–4,66. Selanjutnya, hasil analisis morfologi dari citra SEM-EDS dan analisis mineralogi berdasarkan pengukuran XRD menunjukkan dominasi jenis mineral magnetik pada sampel sedimen adalah magnetit. Mineral magnetit ini memiliki morfologi berbentuk oktahedral sebagai representasi mineral magnetik alami dan ada pula yang berbentuk spherule sebagai representasi mineral magnetik karena adanya proses oksidasi akibat kehadiran material antropogenik pada sedimen Sungai Citarum bagian hilir.

Effect of Hot Isostatic Pressing on the Microstructure of Single Crystal Ni-Based Superalloy DD10

2013 ◽  
Vol 747-748 ◽  
pp. 772-776
Author(s):  
Li Jun Liu ◽  
Ming Xue ◽  
Jing Yang Chen ◽  
La Mei Cao
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Interdendritic Region ◽  
Hot Isostatic Pressing ◽  
Optical Microscope ◽  
Dendrite Core ◽  
Dendritic Segregation ◽  
Third Generation ◽  
Isostatic Pressing ◽  
Scanning Electron

The effects of hot isostatic pressing on the microstructures of a third generation single crystal Ni-based superalloy DD10 were investigated by using optical microscope (OM), scanning electron microscope (SEM), electron microprobe analyzer (EPMA). The results showed that the micropores in the interdendritic region were eliminated completely after hot isostatic pressing at 1320 and 150MPa. Meanwhile, the morphology of γ precipitates changed to be more cuboidal and the distribution of γ precipitates in both dendrite core and interdendritic region became more uniform after hot isostatic pressing. Hot isostatic pressing also promoted the homogenization of the composition between dendrite core and interdendritic region and the dendritic segregation of Re, W, Al and Ta was decreased.

In-situ tensile testing of single-crystal molybdenum-alloy fibers with various dislocation densities in a scanning electron microscope

2011 ◽  
Vol 27 (3) ◽  
pp. 508-520 ◽  
Author(s):  
Kurt E. Johanns ◽  
Andreas Sedlmayr ◽  
P. Sudharshan Phani ◽  
Reiner Mönig ◽  
Oliver Kraft ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Tensile Testing ◽  
Molybdenum Alloy ◽  
Dislocation Densities ◽  
Image Position ◽  
Scanning Electron ◽  
In Situ Tensile Testing

Abstract

scholarly journals Synthesis ofMnO2Microfiber with Secondary Nanostructure by Cotton Template

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Huan-qin Wang ◽  
Ming-bo Zheng ◽  
Jin-hua Chen ◽  
Guang-bin Ji ◽  
Jie-ming Cao
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Surface Area ◽  
Single Crystal Structure ◽  
Bet Surface Area ◽  
Low Concentration ◽  
Adsorption Desorption ◽  
Scanning Electron

HierarchicalMnO2microfibers were prepared by using cotton as the template andKMnO4as the precursor via an ultrasonic assistance route. The results of scanning electron microscope characterization showed that the concentration ofKMnO4had a significant effect on the morphology ofMnO2microfiber. At low concentration ofKMnO4, the microfiber was composed ofMnO2nanorods with single crystal structure. With increasing the concentration ofKMnO4, the secondary nanostructure ofMnO2microfibers had a transformation from nanorod to nanoparticle. The results ofN2adsorption-desorption analysis indicated thatMnO2microfibers had BET surface area of about 25 m2/g. This synthesis provides a new way to control the secondary nanostructure ofMnO2microfiber by adjusting the concentration of precursor. Furthermore, the mechanism for the replication was proposed and discussed.

Sign in / Sign up

Export Citation Format

Share Document