Major Progress in HIRFL-CSR Debugging Achieved

Recently, a research team at the Institute of Modern Physics, CAS made a significant progress in the debugging of the Heavy Ion Research Facility in Lanzhou - Cooler Storage Ring (HIRFL-CSR), one of the state key scientific research projects. On Oct. 15th, researchers stripped and implanted 7Mev 4+ carbon ion beam into the accelerator. When the speed is accelerated to 1000Mev/u, the number of ions in the ring amounted to 2×108. Both the two indicators exceed the previously designed benchmarks of 900Mev/u and 1×108 and are at the highest level in the world, only second to those obtained by EU and USA.

CAS Research Results on New Materials under High Magnetic Field Published

Aresearch team led by Ma Yanwei from the Institute of Electrical Engineering, CAS has conducted a series of studies on the synthesis of new materials under the extreme conditions of high magnetic fields and made significant progress recently. For the first time, they conducted experimental study on the magnetic thin film of YNixMn1-xO3prepared by annealing under large magnetic field. During the experiment, it is found that the ferromagnetic transition temperature is significantly enhanced after post annealing in the presence of an 8 T magnetic field. Characterization study shows that the microstructure is affected, obtaining larger grains of uniform size when films are annealed under a magnetic field. The improvement in the ordering temperature of all films is interpreted in terms of the grain growth caused by the magnetic-field driving force for boundary motion where the exchange coupling is high.

The work is regarded by international peers as one pioneering job in the field of the synthesis of new materials under high magnetic field and was published in the Oct. 9 issue of the Applied Physics Letters (Appl. Phys. Lett. 89 (2006)152505) under the American Institute of Physics.

Generalized Model for Determining Metal-Induced
Reconstruction of Compound Semiconductor Surfaces

Recently, CAS physicists made a major progress in the reconstruction of compound semiconductor surfaces. Based on more than 3 years efforts of theoretical analysis, first-principles calculations, and experimental observations, Zhang Lixin, a doctoral student at the Institute of Physics (IOP), CAS established a generic guiding principle, embodied in generalized electron counting (GEC), that governs the surface reconstruction of compound semiconductors induced by different metal adsorbates. The work has been completed under the guidance of Zhang's tutor Wang En'ge and in cooperation with physicists in and outside IOP. The model has been proposed to serve as the new guiding principle for the in-depth understanding of the metal-induced surface reconstruction of compound semiconductors and the further study of formation of doped nanocluster as well as their corresponding physical properties.

The feat was reported in the Sep. 22nd issue of the Physical Review Letters (Phys. Rev. Lett. 97,126103 (2006)).

New Progress in Organic Field-effect Transistors

Recently, scientists from the Key Laboratory of Organic Solids Center for Molecular Sciences of the Institute of Chemistry, CAS made a new progress in the work over the organic field-effect transistors (OFETs) fabricated with vapor-deposited films of 1-imino nitroxide pyrene used as the semiconductor materials. The research group comprised Research Fellows Liu Yunqi and Zhang Deqing, Zhu Daoben, Member of CAS, and their postgraduate students. Relevant research result, for which China invention patent has been applied, was reported in the recent issue of the Journal of the American Chemical Society (J.Am.Chem.Soc.2006,Vol.128,No.4).

A Research Result in Cosmic Ray-spotting Published in Science

On the basis of a systematic analysis of nearly 40 billion cosmic ray events in a nine-year observation at Yangbajing Cosmic Ray Observation Station (YCROS) in Tibet, which was built in the early 1990s, a Sino-Japanese consortium of Tibet Air Shower Arrays (known as the Tibet ASγ Collaboration) reported in the Oct. 20th issue of the Science their work over the anisotropy of the high energy cosmic rays as well as the rotating motion of cosmic-ray plasma, interstellar gas and stars around the center of the Milky Way galaxy. The result is hailed as a milestone achievement in the cosmic studies by the editor of the journal.

These results have provided valuable observation information for the research in the cosmic-ray origination, acceleration and transmission. Meanwhile, they also lend major support for the further studies of the density wave of galactic scale magnetic fluid and the synchrotron radiation detection measures.

Novel Method for the Synthesis of Semiconductor Nanotubes

Recently, a research team led by Researcher Fellow Zhu Yingjie from the Shanghai Institute of Ceramics, CAS made significant progress in the design and controllable fabrication of IV-VI compound semiconductor nanotubes. The researchers invented a new method for the biomolecule-assisted self-assembly of nanocrystals, where a range of lead chalcogenide (PbS, PbSe, PbTe) nanotubes with obvious quantum confinement effect were skillfully synthesized at room temperature by using the biomolecule with multifunctional gene. The work shows good application prospect in the fields of infrared imaging and laser, semiconductor infrared detector, photoresistor, solar battery, thermo-electric device, etc.