4.2K低温扫描隧道显微镜的研制及2H-NbSe_2中电荷密度波的观测

4.2K low temperature scanning tunneling microscope and its application to the observation of charge density wave in 2H NbSe 2ST]

本文详细描述了自行设计和研制的４．２Ｋ低温扫描隧道显微镜的结构和性能，并报导了利用这台低温扫描隧道显微镜在４．３Ｋ下对２Ｈ－ＮｂＳｅ２单晶中的电荷密度波及高温超导体Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏ８＋δ单晶电子隧道谱的观测结果。

We describe a home built low temperature scanning tunneling microscope (LT STM) which can work at room temperature,77K and 4 2K.The LT STM main body is made of machinable glass ceramic (MACOR) which provides highly mechnical rigidity and thermal stability.The main body includes also a piezo linear step motor which realizes automatically the precise aproach of tip to sample.The LT STM system are also consisted of a two stage vibration isolation consisting of spring suspensaion and an air table,a 2×10 -4 Pa oil free high vacuum pumping line,a 6 tesla superconducting magnet,a helium Dewar,electronic control system and windows interfaced STM software.With this LT STM atomically resolved images of HOPG were obtained at both room temperature and 4.3K.We have also observed a high quality atomic modulation and the charge density wave modulation and possiblly the periodic lattice distortion in crystal 2H NbSe 2.We have also measured the tunneling spectroscopies of high temperature superconductor Bi2212 at 4.3K by using this home built LT STM.