ELASTIC AND INELASTIC ELECTRON TUNNELING IN MAGNETIC METAL/MAGNETIC LAYERED SEMICONDUCTOR HETEROJUNCTIONS

我们研究了具有铁磁金属电极和/或反铁磁绝缘层的金属/绝缘体/金属(MIM)结中的弹性和非弹性电子隧穿(IET)。绝缘层是由层状半导体、用于反铁磁层的过渡金属硫代磷酸盐和用于非磁性层的III-VI化合物的单晶切割而成的单晶薄膜。几种夹在铁磁性Fe电极之间的MNPS_3反铁磁绝缘层的MIM结表现出电流-电压特性的隧道电流，尽管这些结具有有效的金属电流路径并联和/或串联到结中的隧道电流路径。此外，还获得了有关MIM结中隧穿现象的一些补充信息：(A)Pb/MnPSe_3/Pb结的隧穿特性显示了隧穿电子与MnPSe_3反铁磁磁子和MnPSe_3声子之间的相互作用，(B)Sb/Gas/Sb和Sb/Gas/Pb结的隧穿光谱都反映了半金属Sb的能带结构。与非对称Sb/GAs/Pb结相比，Sb/Gas/Sb对称结中Sb声子和气体声子引起的IET过程减少.(C)在Al/Gas/Pb结的隧穿特性中首次观察到Al的自能效应.此外，从Ag/Gas/Pb和Cu/Gas/Pb结的隧道谱中还推断出了Ag和Cu的自能效应。(D)In_2/3&Gt；PS_3单晶的光吸收光谱显示出间接吸收边。得到了激子能隙和动量守恒声子的能量值。

We have studied elastic and inelastic electron tunneling (IET) in metal/insulator/metal (MIM) junctions having ferromagnetic metal electrodes and/or antiferromagnetic insulating layrs. The insulating layrs are single crystal thin films cleaved from the single crystals of layred semiconductors, transition metal chalcogeno-phosphates for antiferromagnetic layrs and III-VI compounds for nonmagnetic layrs. Several MIM junctions with an MnPS_3 antiferromagnetic insulating layr sandwiched between two ferromagnetic Fe electrodes show tunnel current in current-voltage characteristics, although the junctions have effectively the metallic current paths parallel and/or series to tunnel current paths in the junctions. Moreover, some additional informations about tunneling phenomena in MIM junctions were also obtained :(a) The tunneling characteristics in Pb/MnPSe_3/Pb junctions show the interactions between tunneling electrons and MnPSe_3 antiferromagnetic magnons as well as MnPSe_3 phonons.(b) Both tunneling spectra for Sb/GaS/Sb and Sb/GaS/Pb junctions reflect band structures in semimetallic Sb. The IET processes due to Sb phonons as well as GaS ones in the symmetrical Sb/GaS/Sb junctions are reduced due to small Fermi surfaces of Sb compared with those in the asymmetrical Sb/GaS/Pb junctions.(c) Self energy effects of Al are observed for the first time in the tunneling characteristics in Al/GaS/Pb junctions. Furthermore, self enrgy effects of Ag and Cu are inferred from the tunneling spectra for Ag/GaS/Pb and Cu/GaS/Pb junctions.(d) The optical absorption spectra of In_<2/3>PS_3 single crystals show an indirect absorption edge. The energy values of the exciton gap and those of the momentum conserving phonons in In_<2/3>PS_3 are reduced from the spectra.