Single Crystal Growth of YBa2Cu4O8 and Y2Ba4Cu7O15 Under High Oxygen Pressure

1991 ◽  
Vol 251 ◽  
Author(s):  
T. Miyatake ◽  
T. Takata ◽  
K. Yamaguchi ◽  
K. Takamuku ◽  
N. Koshizuka ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Single Crystal ◽  
Single Crystals ◽  
Oxygen Pressure ◽  
Maximum Size ◽  
Single Crystal Growth ◽  
Mixed Gas ◽  
High Oxygen Pressure

ABSTRACTWe investigate the crystal growth of YBa2Cu4O8 (124) and Y2Ba4Cu7O15 (247) in Al2O3 crucibles at an oxygen partial pressure of 20MPa employing an O2- HIP apparatus in a mixed gas environment of Ar-20%O2. Various melts compositions, rich in Ba and Cu, are explored to optimize crystal growth of 124. Large 124 single crystals up to a size of 1×0.5×0.05mm3 are obtained from compositions with about 65˜67%CuO. 247 single crystals having a maximum size of 3×1.5×0.05mm3 are grown from the same composition of melts. 124 crystals exhibit superconductivity at 75K. 247 crystals show Tc of 20K.

Single-crystal growth and characterization of the Pb0.5Sr2.5Y1−xCaxCu2Oy system

1995 ◽  
Vol 10 (9) ◽  
pp. 2211-2215 ◽  
Author(s):  
H. Jin ◽  
N.L. Wang ◽  
Y. Chong ◽  
M. Deng ◽  
L.Z. Cao ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Single Crystals ◽  
Single Crystal Growth ◽  
Optimum Conditions ◽  
Flux Method ◽  
Ca Doping ◽  
Spontaneous Nucleation

Two kinds of methods such as spontaneous nucleation from flux-free stoichiometric melt and CuO flux method have been used for the growth of Pb0.5Sr2.5Y1−xCaxCu2Oy single crystals. The morphologies, phases, and compositions occurring in the crystals grown from the two kinds of methods were compared systematically. Optimum conditions for the growth of larger 1212 phase single crystals are x =0.15, 0.25, and 0.35. The lattice parameters of the crystals with the 1212 phase were found to be increasing upon Ca doping. The resistivity behavior of the PbSrYCaCuO single crystals with the 1212 phase both in the state of as-grown and after extended annealings under various oxygen partial pressure was also discussed briefly.

Crystal growth of YBa2Cu3O7 by the SRL-CP method under low oxygen partial pressure atmosphere

1994 ◽  
Vol 9 (8) ◽  
pp. 1946-1951 ◽  
Author(s):  
M. Nakamura ◽  
Y. Yamada ◽  
Y. Shiohara
Keyword(s):  
Crystal Growth ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Single Crystals ◽  
Oxygen Pressure ◽  
Crystal Surface ◽  
Nitrogen Atmosphere ◽  
Low Oxygen ◽  
Pure Nitrogen ◽  
Rich Liquid

Single crystals of YBa2Cu3O7−x (Y123) were grown by a modified top-seeded crystal pulling method using a BaO-CuO solution with the solid Y2BaCuO5 (Y211) as a solute in an yttria crucible [the so-called solute-rich liquid crystal pulling (SRL-CP) method] under 2% oxygen partial pressure atmosphere [P(O2) = 0.02 atm]. According to the pseudo-binary phase diagrams of Lee and Lee,1 the temperature of Y123 crystal growth was expected to be lower for 0.02 atm oxygen pressure than for 0.21 atm oxygen pressure. The single crystals grown under P(O2) = 0.02 atm and cooled under the same atmosphere after the separation of crystal from a solution had twins near the microcracks on the crystal surface. On the other hand, the single crystals grown under P(O2) = 0.02 atm and cooled under pure nitrogen atmosphere (6N) showed no twin structure. These results indicate that twins did not form during crystal growth but formed due to tetragonal-orthorhombic transition as a consequence of oxygenation at cooling under low oxygen partial pressure.

scholarly journals High oxygen pressure single crystal growth of highly Ca-doped spin ladder compound Sr14−xCaxCu24O41 (x>12)

2011 ◽  
Vol 327 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Guochu Deng ◽  
D. Mohan Radheep ◽  
R. Thiyagarajan ◽  
Ekaterina Pomjakushina ◽  
Shuang Wang ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Oxygen Pressure ◽  
Single Crystal Growth ◽  
High Oxygen ◽  
Spin Ladder ◽  
High Oxygen Pressure

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

scholarly journals Growth of single crystals in the (Na1/2Bi1/2)TiO3–(Sr1–xCax)TiO3 system by solid state crystal growth

2021 ◽  
Author(s):  
Phan Gia Le ◽  
Huyen Tran Tran ◽  
Jong-Sook Lee ◽  
John G. Fisher ◽  
Hwang-Pill Kim ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Solid State ◽  
Single Crystal ◽  
Single Crystals ◽  
Piezoelectric Properties ◽  
Single Crystal Growth ◽  
Crystal Growth Rate ◽  
Large Strains ◽  
Growth Technique ◽  
The Matrix

AbstractCeramics based on (Na1/2B1/2)TiO3 are promising candidates for actuator applications because of large strains generated by an electric field-induced phase transition. For example, the (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 system exhibits a morphotropic phase boundary at x = 0.2–0.3, leading to high values of inverse piezoelectric constant d*33, which can be further improved by the use of single crystals. In our previous work, single crystals of (Na1/2B1/2)TiO3-SrTiO3 and (Na1/2B1/2)TiO3-CaTiO3 were grown by the solid state crystal growth technique. Growth in the (Na1/2B1/2)TiO3-SrTiO3 system was sluggish whereas the (Na1/2B1/2)TiO3-CaTiO3 single crystals grew well. In the present work, 0.8(Na1/2Bi1/2)TiO3-0.2(Sr1−xCax)TiO3 single crystals (with x = 0.0, 0.1, 0.2, 0.3, 0.4) were produced by the solid state crystal growth technique in an attempt to improve crystal growth rate. The dependence of mean matrix grain size, single crystal growth distance, and electrical properties on the Ca concentration was investigated in detail. These investigations indicated that at x = 0.3 the matrix grain growth was suppressed and the driving force for single crystal growth was enhanced. Replacing Sr with Ca increased the shoulder temperature Ts and temperature of maximum relative permittivity Tmax, causing a decrease in inverse piezoelectric properties and a change from normal to incipient ferroelectric behavior.

Flux-assisted single crystal growth and heteroepitaxy of perovskite-type mixed-metal borohydrides

CrystEngComm ◽  
2015 ◽  
Vol 17 (13) ◽  
pp. 2682-2689 ◽  
Author(s):  
Pascal Schouwink ◽  
Adrien Ramel ◽  
Enrico Giannini ◽  
Radovan Černý
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Single Crystal Growth ◽  
Mixed Metal ◽  
Perovskite Type

Single crystals of mixed-metal perovskite-type borohydride KCa(BH4)3 are prepared by using an easily generalized flux melting procedure based on eutectic borohydride systems.

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