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Zone Method (zone + method)

Distribution by Scientific Domains
Physics and Astronomy75%

Selected Abstracts

Floating zone growth of CuO under elevated oxygen pressure and its relevance for the crystal growth of cuprates

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 1-2 2005
G. Behr
Abstract CuO single crystals have been grown from the melt by a floating zone method with optical heating at elevated oxygen pressures 3.5 to 5.5 MPa and growth rates as high as 10 mm/h. Melting experiments and recalculated Cu-O phase diagram data show that CuO melts incongruently. The melting temperature increases and the concentration difference between the melt and the CuO phase decreases for rising oxygen partial pressure. Accordingly, increasing the oxygen partial pressure improves the growth process by reducing both the significant oxygen loss during melting as well as the composition difference at the growth interface. The results on CuO provide important information for the crystal growth of more complex cuprates. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

High-Temperature Tensile Strength of Er2O3 -Doped ZrO2 Single Crystals

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2006
José Y. Pastor
The deformation and fracture mechanisms in tension were studied in single-crystal Er2O3 -doped ZrO2 monofilaments processed by the laser-heated floating zone method. Tensile tests were carried out between 25° and 1400°C at different loading rates and the dominant deformation and fracture mechanisms were determined from the shape of the stress,strain curves, the morphology of the fracture surfaces, and the evidence provided by monofilaments deformed at high temperature and broken at ambient temperature. The tensile strength presented a minimum at 600°,800°C and it was controlled by the slow growth of a crack from the surface. This mechanism was also dominant in some monofilaments tested at 1000°C and above, while others showed extensive plastic deformation before fracture at these temperatures. The strength of plastically deformed monofilaments was significantly higher than those which failed by slow crack growth due to the marked strain hardening capacity of this material. [source]

Wet chemical etching behavior of ,-Ga2O3 single crystal

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2008
Shigeo Ohira
Abstract Wet chemical etching behavior of ,-Ga2O3 single crystal was investigated to evaluate its chemical stability and to explore etchants for ,-Ga2O3 single crystal. Undoped and Sn-doped ,-Ga2O3 single crystals were grown by the floating zone method, and (100)- and (001)-oriented samples were chemical-mechanical-polished to wafers. The samples were wet chemically etched in solutions such as HCl, H2SO4, HNO3, HF, H2O2:H2SO4:H2O=1:4:1, KOH, and NaOH. The samples were chemically stable against both acids and alkalis except HF and NaOH. Aqueous HF solution was found to etch ,-Ga2O3 uniformly at room temperature. The etch rate increased with increasing immersion time and HF content. Anisotropy of etch rate was observed between the (100) and (001) planes. The etch rate of Sn-doped ,-Ga2O3 was lower than that of undoped ,-Ga2O3, and the etch rate decreased with increasing Sn doping content. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Ferromagnetism in diluted magnetic semiconductors Ti1,xMxO2 (M = V, Cr, Mn and Ni)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2006
N. Shimizu
Abstract Diluted magnetic semiconductors Ti1,xMxO2 (M = V, Cr, Mn, Fe, Ni and Cu) with x = 0.005 have been studied in a single crystal form. We have succeeded in growing Ti0.995M0.005O2 single crystals for M = V, Cr, Mn and Ni with the Rutile crystal structure by floating zone method, while it was not successful for M = Fe and Cu. It is found that the physical properties of these single crystals are greatly influenced by growth atmospheres. Among these crystals grown in a low oxygen partial pressure, Ti0.995M0.005O2 with M = Ni exhibited a typical ferromagnetic behavior even at room temperature. Crystallographic properties as well as magnetism have been studied. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]