Synthesis of Si nanosheets by a chemical vapor deposition process and their blue emissions.

We synthesized free-standing Si nanosheets (NSs) with a thickness of about <2 nm using a chemical vapor deposition process and studied their optical properties. The Si NSs were formed by the formation of frameworks first along six different <110> directions normal to [111], its zone axis, and then by filling the spaces between the frameworks along the <112> directions under high flow rate of processing gas. The Si NSs showed blue emission at 435 nm, and absorbance and photoluminescence (PL) excitation measurements indicate that enhanced direct band transition attributes to the emission.

Fabrication of Coaxial Si(1-x)Ge(x) Heterostructure Nanowires by O(2) Flow-Induced Bifurcate Reactions.

We report on bifurcate reactions on the surface of well-aligned Si(1-x)Ge(x) nanowires that enable fabrication of two different coaxial heterostructure nanowires. The Si(1-x)Ge(x) nanowires were grown in a chemical vapor transport process using SiCl(4) gas and Ge powder as a source. After the growth of nanowires, SiCl(4) flow was terminated while O(2) gas flow was introduced under vacuum.

Structural and chemical characterization of Mn doped GaN nanowires by X-ray absorption spectroscopy.

We report on structural chemical state of doped Mn atoms in single crylstalline Mn doped GaN nanowires by X-ray absorption spectroscopy. Anomalous X-ray scattering and K-edge X-ray absorption fine structure measurement make it clear that Mn atoms substitute the Ga sites and they largely take part in the wurtzite network of host GaN. X-ray absorption and X-ray magnetic circular dichroism spectra at Mn L(2,3)-edges show that doped Mn has local magnetic moment and the electronic configuration of the doped Mn is mainly 3d(5) component.

Room-temperature ferromagnetism in Cu doped GaN nanowires.

We report magnetism in Cu doped single-crystalline GaN nanowires. The typical diameter and the length of the Ga1-xCuxN nanowires (x = 0.01, 0.