Papers by Keyword: Melt Growth

Abstract: We evaluated optical and scintillation properties of a Cr 0.5%:Y₃Ga₅O₁₂ (YGG) and Cr 0.5%:Y₃Al₅O₁₂ (YAG) crystals grown by the micro-pulling down method for infrared emission scintillators. In the photoluminescence and X-ray induced radioluminescence measurements, the emissions peaks of Cr:YGG were located in the longer wavelength than those of Cr:YAG. Radioluminescene spectrum of Cr:YGG had a broad peak at 716 nm related to Cr^{3+ 2}E→⁴A₂ and ⁴T→⁴A₂ transitions.

Abstract: Well-characterised samples such as single crystals, bi-, tri- or multicrystals are needed for basic studies of properties of solids. Growth of such metallic structures by means of the floatingzone melting technique is demonstrated for iron base alloys, FeAl intermetallics and NiTi shape memory alloy.

Abstract: By introducing ZrO2(4Y) powder of suitable content into the thermit and based on oxidation-reduction reaction of the thermit and liquid-liquid phase separation of ceramics/metal under gravity, Al2O3/ZrO2(4Y) composite ceramics have been prepared through melt-growth with eutectic reaction under high degree of undercooling from SHS process. It has been found that the ceramics were composed of major rod-shaped sapphires with 8.0~12.0 aspect ratios and minor plate-like α-Al2O3 grains, and within the sapphires t-ZrO2 nano-micron fibers were embedded. Flexural strength and fracture toughness were measured to be 1256MPa and 13.2MPa·m1/2. It was obtained that a number of low energy interfaces (the interface distance on nano-micron scale) between two Al2O3/ZrO2 (4Y) phases and the strong compressive residual stress in the sapphires made the sapphires reinforced, forcing the crack to propagate along the rod-shaped sapphires; meanwhile, crack-bridging and pull-out of the sapphires, crack - bridging and frictionally interlocked effects of plate-like α-Al2O3 grains in the wake of crack tip also rendered the crack stabilization to arise.