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[en] Fe₂VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe₂VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy measurements showed that the carrier density and scattering time had little sample-to-sample variation or temperature dependence for near-stoichiometric samples. FTIR and DC resistivity suggest that the transport properties of Fe₂VAl are influenced by both localized and delocalized carriers, with the former primarily responsible for the negative temperature coefficient of resistivity. Magnetization measurements reveal that near-stoichiometric samples have superparamagnetic clusters with at least two sizes of moments. X-ray photoemission from Fe core level showed localized magnetic moments on site-exchanged Fe. They conclude that in Fe₂VAl, antisite disorder causes significant modification to the semi-metallic band structure proposed by LDA calculations. With antisite disorder considered, they are now able to explain most of the physical properties of Fe₂VAl

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[en] VAX-8350 calculational centre was set up in 1991. Its main purpose is to provide software and hardware for the computer control system of SSC in order to support the needs of the beam tuning and operating of HIRFL. At the same time, it provides a computational and graphic work environment for the scientific calculation, the experimental data process and analysis, the graphic process for users of inside and outside of IMP. During 1991, it ran for 3500 h for the beam tuning and operating of SSC, the magnet field mapping of SFC, the scientific calculation and the experimental data process. There were 80 users to develop their different work by using its equipment. All of equipment was maintained by itself technicians. About 20 sets of fault equipment were restored to keep the system always stable and reliable

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[en] Chemically homogeneous SrBi₂Ta₂O₉ (SBT) sol was synthesized using ethoxy tantalum, strontium acetate, and bismuth subnitrate as starting materials, methoxyethylene as a solvent and acetic acid (HOAc) as a catalyst. Single-phased perovskite phase SBT ferroelectric ultrafine powder was obtained after the dried gel was treated at 350 deg. C for 30 min and calcined at 800 deg. C for 1 h. FT-IR, XRD, TEM and TG-DTA were employed to investigate the transformation processes of sol to gel and gel to ultrafine SBT powder. Acetic acid not only acts as an acid catalyst, but also changes the alkoxide precursor as a ligand at a molecular level. Bidentate acetates replace OR groups and are directly bounded to the tantalum, leading to the formation of Ta (OR)_x(OAc)_5-x. The perovskite SBT phase formed via intermediate phase Bi₃TaO₇ and a Bi-deficient pyrocholore phase

[en] Since the first C⁶⁺ beam were extracted from HIRFL (Heavy Ion Research Facility of Lanzhou) on Dec. 12, 1988, C⁶⁺(50 MeV/u, 75 MeV/u), O⁸⁺(50 MeV/u), Ne⁸⁺(25 MeV/u) Ar¹⁵⁺ (25 MeV/u) and other beams have been accelerated for the testing of the experimental terminals and the experimental research on heavy ion nuclear physics, atomic physics, nuclear chemistry, biology and material science. The beam emittance is less than 8 π mm mrad and the energy spread is less than 0.3%. The 10 GHz ECR ion source and its beam line as well as the external injection system were put into operation in May, 1992 with quite well performance. Meanwhile a lot of improvements of the injector SFC had been done to meet the requirements of the external injection systems and to improve the performance of SFC. Many improvements of the vacuum, RF, control and other systems of the main accelerator SSC of HIRFL were finished. The operation of HIRFL are also presented