One-Dimensional Growth of Li2NiPO4F Single Crystals from Intermediate LiNiPO4 Crystal Surface Using KCl–KI Fluxes

It is necessary to formpinning centers in superconductors to allow the flow of large currents throughthe specimens. To clarify the properties of pinning centers, it is preferableto investigate single crystals. In this study, heat treatment was used to dopevarious oxides into Bi2Sr2CaCu2Ox(Bi-2212) single crystals prepared by self-flux methods and the criticalcurrent (Ic) was measured. The oxides used in this study were Al2O3and the rare earth oxides Er2O3and Nd2O3. At 77K, Nd2O3and Er2O3 are magnetic, whereas Al2O3is nonmagnetic. The Ic of the samples were measured as a current per width of 1cm (Ics). The resulting Ics of the Bi-2212 single crystal was 2.8A/cm and thatof the Al2O3 doped Bi-2212 sample was 4.5A/cm. Comparedwith these samples, doping the other rare earth oxides gave Ics values inexcess 10A/cm. The results indicated that the doping oxides were effective inoperating as pinning centers in the samples. We assumed the current path in asingle crystal, and calculated the Ics by superconducting current simulation.The results indicated that the oxides permeated from a crystal surface in aporous shape. The oxides increase the current which flow in the Cu-O2planes that are parallel to the a-b plane.

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Synthesis of azamacrocycle stabilized palladium nanoparticles: Controlled size and one-dimensional growth

Journal of Chemical Sciences ◽

10.1007/s12039-011-0165-5 ◽

2011 ◽

Vol 123 (6) ◽

pp. 875-881 ◽

Cited By ~ 10

Author(s):

JEYARAMAN ATHILAKSHMI ◽

DILLIP KUMAR CHAND

Keyword(s):

Palladium Nanoparticles ◽

One Dimensional ◽

Dimensional Growth

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Unexpected photoluminescence properties from one-dimensional molecular chains

Nanoscale ◽

10.1039/c5nr05795g ◽

2016 ◽

Vol 8 (3) ◽

pp. 1456-1461 ◽

Cited By ~ 2

Author(s):

Ye Yuan ◽

Mingguang Yao ◽

Shuanglong Chen ◽

Shijie Liu ◽

Xigui Yang ◽

...

Keyword(s):

Single Crystals ◽

Photoluminescence Properties ◽

One Dimensional

Unlike bulk iodine, iodine molecular chains formed inside one dimensional (1D) nanochannels of AlPO4-5 (AFI) single crystals show unexpected PL behavior.

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Visualization of one-dimensional diffusion and spontaneous segregation of hydrogen in single crystals of VO2

Nanotechnology ◽

10.1088/0957-4484/27/34/345708 ◽

2016 ◽

Vol 27 (34) ◽

pp. 345708 ◽

Cited By ~ 4

Author(s):

T Serkan Kasırga ◽

Jim M Coy ◽

Jae H Park ◽

David H Cobden

Keyword(s):

Single Crystals ◽

One Dimensional ◽

Dimensional Diffusion

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Potential of using inert gas flows for controlling the quality of as-grown silicon single crystal

Modern Electronic Materials ◽

10.3897/j.moem.6.1.53248 ◽

2020 ◽

Vol 6 (1) ◽

pp. 1-7

Author(s):

Tatyana V. Kritskaya ◽

Vladimir N. Zhuravlev ◽

Vladimir S. Berdnikov

Keyword(s):

Single Crystal ◽

Carbon Content ◽

Single Crystals ◽

Gas Flow ◽

Thermal Stresses ◽

Crystal Surface ◽

Gas Flows ◽

Reaction Products ◽

Crystal Silicon ◽

Argon Gas

We have improved the well-known Czochralski single crystal silicon growth method by using two argon gas flows. One flow is the main one (15–20 nl/min) and is directed from top to bottom along the growing single crystal. This flow entrains reaction products of melt and quartz crucible (mainly SiO), removes them from the growth chamber through a port in the bottom of the chamber and provides for the growth of dislocation-free single crystals from large weight charge. Similar processes are well known and have been generally used since the 1970s world over. The second additional gas flow (1.5–2 nl/min) is directed at a 45 arc deg angle to the melt surface in the form of jets emitted from circularly arranged nozzles. This second gas flow initiates the formation of a turbulent melt flow region which separates the crystallization front from oxygen-rich convective flows and accelerates carbon evaporation from the melt. It has been confirmed that oxygen evaporated from the melt (in the form of SiO) acts as transport agent for nonvolatile carbon. Commercial process implementation has shown that carbon content in as-grown single crystals can be reduced to below the carbon content in the charge. Single crystals grown with two argon gas flows have also proven to have highly macro- and micro-homogeneous oxygen distributions, with much greater lengths of single crystal portions in which the oxygen concentration is constant and below the preset limit. Carbon contents of 5–10 times lower than carbon content in the charge can be achieved with low argon gas consumption per one growth process (15–20 nl/min vs 50–80 nl/min for conventional processes). The use of an additional argon gas flow with a 10 times lower flowrate than that of the main flow does not distort the pattern of main (axial) flow circumvention around single crystal surface, does not hamper the “dislocation-free growth” of crystals and does not increase the density of microdefects. This suggests that the new method does not change temperature gradients and does not produce thermal shocks that may generate thermal stresses in single crystals.

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