Individual titanyl phthalocyanine(TiOPc)molecules on ultrathin sodium chloride striped films grown on Cu(110)exhibit two different topographies with 8-lobes and 6-lobes when imaged by scanning tunneling microscopy(STM...Individual titanyl phthalocyanine(TiOPc)molecules on ultrathin sodium chloride striped films grown on Cu(110)exhibit two different topographies with 8-lobes and 6-lobes when imaged by scanning tunneling microscopy(STM).Direct images of the molecular orbitals of the molecules with 8-lobes are obtained,indicating that the electronic structure of the TiOPc molecule are decoupled from the metallic substrate.For the TiOPc molecule with 6-lobes,the STM images at negative and positive bias polarities show the same structures as 2-fold symmetry except for the 90°rotation with respect to each other.This phenomenon may be attributed to the splitting of the two former degenerate lowest unoccupied molecular orbitals due to the negative charging of the molecule.The identification of the molecular orbital splitting on the ultrathin insulating layer could deepen the understanding of the intrinsic properties of semi-conducting molecules.展开更多
We report the study of a low temperature cluster glass state in 5% Mn-doped UGa3 heavy fermion compound. This compound transforms from a paramagnetic state to a spin-cluster glass state, which is confirmed by measurin...We report the study of a low temperature cluster glass state in 5% Mn-doped UGa3 heavy fermion compound. This compound transforms from a paramagnetic state to a spin-cluster glass state, which is confirmed by measuring the dc susceptibility and magnetization. The ac susceptibility exhibits a frequency-dependent peak around Tf, which provides direct evidence of the cluster glass state. By analyzing the field-dependent magnetization and frequency-dependent ac susceptibility in detail, we deduce that this compound forms a spin-cluster glass state below Tf.展开更多
不同于扫描隧道显微镜(scanning tunneling microscope,STM),原子力显微镜(atomic force microscope,AFM)主要通过探测针尖和样品间的相互作用力获得样品表面信息,不需要导电的样品,可以研究比STM更为广泛的样品体系,自发明以来迅速成...不同于扫描隧道显微镜(scanning tunneling microscope,STM),原子力显微镜(atomic force microscope,AFM)主要通过探测针尖和样品间的相互作用力获得样品表面信息,不需要导电的样品,可以研究比STM更为广泛的样品体系,自发明以来迅速成为基础科学和应用研究领域中一种强有力的工具.近几年发展起来的基于qPlus技术的非接触式原子力显微镜(qPlus-noncontact AFM,qPlus-NC-AFM),通过关键部件原子力传感器的改进,进一步拓展了原子力显微镜的探测能力,从而在许多研究方向上取得了重要突破.本文介绍了qPlus-AFM的基本工作原理及其在基础科学研究领域中的最新研究进展,并对其进一步的发展进行了展望.展开更多
基金supported by the National Key Basic Research Program of China(973)(2006CB921502)Knowledge Innovation Program of the Chinese Academy of Sciences(KJCX2-YW-M04)~~
基金Supported by the National Basic Research Program of China(2012CB933001)the National Natural Science Foundation of China(21173058,21203038).
文摘Individual titanyl phthalocyanine(TiOPc)molecules on ultrathin sodium chloride striped films grown on Cu(110)exhibit two different topographies with 8-lobes and 6-lobes when imaged by scanning tunneling microscopy(STM).Direct images of the molecular orbitals of the molecules with 8-lobes are obtained,indicating that the electronic structure of the TiOPc molecule are decoupled from the metallic substrate.For the TiOPc molecule with 6-lobes,the STM images at negative and positive bias polarities show the same structures as 2-fold symmetry except for the 90°rotation with respect to each other.This phenomenon may be attributed to the splitting of the two former degenerate lowest unoccupied molecular orbitals due to the negative charging of the molecule.The identification of the molecular orbital splitting on the ultrathin insulating layer could deepen the understanding of the intrinsic properties of semi-conducting molecules.
基金supported by the Natural Science Foundation of China Academy of Engineering Physic(Grant No.2014A0301013)the National Natural Science Foundation of China(Grant Nos.11304291 and 11504342)
文摘We report the study of a low temperature cluster glass state in 5% Mn-doped UGa3 heavy fermion compound. This compound transforms from a paramagnetic state to a spin-cluster glass state, which is confirmed by measuring the dc susceptibility and magnetization. The ac susceptibility exhibits a frequency-dependent peak around Tf, which provides direct evidence of the cluster glass state. By analyzing the field-dependent magnetization and frequency-dependent ac susceptibility in detail, we deduce that this compound forms a spin-cluster glass state below Tf.
