Figure 1 Expansion of gallium inside a carbon nanotube with increasing temperature. a-c, Changing level of the gallium meniscus at 58℃ (a), 490℃ (b) and 45℃ (c); scale bar, 75nm. d, Height of the gallium meniscus plotted against temperature, measured in steps of 30–50℃; results are averaged (green curve) from closely similar measurements obtained during heating (red) and cooling (blue). The nanothermometer was synthesized in a vertical radiofrequency furnace (which differs from a one-step arc-discharge method). A homogeneous mixture of Ga2O3 and pure, amorphous, active carbon (weight ratio, 7.8:1) was reacted in an open carbon crucible under a flow of pure N2 gas: at 1,360℃, the reaction Ga2O3(solid)&2C(solid)ÕGa2O(vapour)&2CO(vapour) occurs. However, on the inner surface of a pure graphite outlet pipe at the top of the furnace, the temperature is lower (around 800℃), causing the reaction Ga2O(vapour)&3CO(vapour)Õ 2Ga(liquid)&C(solid)&2CO2(vapour) to occur, during which the nanothermometers' are created.

A high-resolution electron microscopy study of β-SiC nanoparticles formed by C+-implantation of single crystal silicon with subsequent annealing has been carried out. The as-implanted sample had a trilayered structure, in which the surface layer, A, and the bottom layer, C, were crystalline but damaged, and the middle layer, B, was amorphous. After annealing this structure, β-SiC particles were formed throughout the trilayered structure but with different forms: a few epitaxial β-SiC nanoparticles in layers A and C, and more random nanoparticles in layer B. The β-SiC nanoparticles, in the size range 2-8nm, should be responsible for the blue-emitting effect of the silicon-based porous β-SiC