Spin-Polarized Scanning Tunneling Microscopy (SPSTM)

1991 ◽  
Vol 231 ◽  
Author(s):  
R. Wiesendanger ◽  
D. Buergler ◽  
G. Tarrach ◽  
I.V. Shvets ◽  
H.-J. Guentherodt
Keyword(s):  
Scanning Tunneling Microscope ◽  
High Spatial Resolution ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Promising Technique ◽  
Polarized Electrons ◽  
Tunneling Microscope ◽  
Magnetic Structures ◽  
Spin Polarized

AbstractWe report on a novel promising technique for the investigation of magnetic structures at surfaces at high spatial resolution, ultimately down to the atomic scale. This technique is based on the observation of vacuum tunneling of spin-polarized electrons by means of a scanning tunneling microscope (STM). We discuss appropriate probe tips for the spin-polarized STM (SPSTM) and describe initial experimental results. We further focus on the information obtained by SPSTM. Finally, the perspectives of SPSTM will be discussed.

Observation of vacuum tunneling of spin-polarized electrons with the scanning tunneling microscope

1990 ◽  
Vol 65 (2) ◽  
pp. 247-250 ◽  
Author(s):  
R. Wiesendanger ◽  
H.-J. Güntherodt ◽  
G. Güntherodt ◽  
R. J. Gambino ◽  
R. Ruf
Keyword(s):  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Polarized Electrons ◽  
Tunneling Microscope ◽  
Spin Polarized

NANOSCALE CHARACTERIZATION BY SCANNING TUNNELING MICROSCOPY

COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 23-50 ◽  
Author(s):  
HAI XU ◽  
XIAN NING XIE ◽  
M. A. K. ZILANI ◽  
WEI CHEN ◽  
ANDREW THYE SHEN WEE
Keyword(s):  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Preparation Methods ◽  
New Developments ◽  
Tunneling Microscope ◽  
Spin Polarized ◽  
Nanoscale Characterization ◽  
Working Principle ◽  
Operational Modes

Nanoscale characterization is a key field in nanoscience and technology as it provides fundamental understanding of the properties and functionalities of materials down to the atomic and molecular scale. In this article, we review the development and application of scanning tunneling microscope (STM) techniques in nanoscale characterization. We will discuss the working principle, experimental setup, operational modes, and tip preparation methods of scanning tunneling microscope. Selected examples are provided to illustrate the application of STM in the nanocharacterization of semiconductors. In addition, new developments in STM techniques including spin-polarized STM (SP-STM) and multi-probe STM (MP-STM) are discussed in comparison with conventional non-magnetic and single tip STM methods.

scholarly journals Atomic-scale spin-polarization maps using functionalized superconducting probes

2021 ◽  
Vol 7 (4) ◽  
pp. eabd7302
Author(s):  
Lucas Schneider ◽  
Philip Beck ◽  
Jens Wiebe ◽  
Roland Wiesendanger
Keyword(s):  
Spin Polarization ◽  
Scanning Tunneling Microscope ◽  
Spin Structure ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Magnetic Impurities ◽  
Impurity States ◽  
Tunneling Microscope ◽  
Spin Polarized ◽  
Strong Spin

A scanning tunneling microscope (STM) with a magnetic tip that has a sufficiently strong spin polarization can be used to map the sample’s spin structure down to the atomic scale but usually lacks the possibility to absolutely determine the value of the sample’s spin polarization. Magnetic impurities in superconducting materials give rise to pairs of perfectly, i.e., 100%, spin-polarized subgap resonances. In this work, we functionalize the apex of a superconducting Nb STM tip with such impurity states by attaching Fe atoms to probe the spin polarization of atom-manipulated Mn nanomagnets on a Nb(110) surface. By comparison with spin-polarized STM measurements of the same nanomagnets using Cr bulk tips, we demonstrate an extraordinary spin sensitivity and the possibility to measure the sample’s spin-polarization values close to the Fermi level quantitatively with our new functionalized probes.

Imaging molecules and metals on metal surfaces by scanning tunneling microscopy

1991 ◽  
Vol 49 ◽  
pp. 370-371
Author(s):  
S. Chiang ◽  
D. D. Chambliss ◽  
V. M. Hallmark ◽  
R. J. Wilson ◽  
J. K. Brown ◽  
...  
Keyword(s):  
High Resolution ◽  
Scanning Tunneling Microscope ◽  
Binding Sites ◽  
Near Neighbor ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Tunneling Microscope ◽  
Lattice Constants ◽  
Stm Images

Using an ultrahigh vacuum scanning tunneling microscope (STM), we have imaged naphthalene molecules adsorbed on Pt(111) and submonolayer metal coverages of Ni, Fe, Ag, and Au on Au(111). The STM is able to observe atomic scale features on both types of systems, giving information on the ordering and binding sites of atoms and molecules on the surface.High resolution STM images of naphthalene on Pt(111) show the molecules as bi-lobed features with three discrete molecular orientations on the surface, 120° apart, as shown for the ordered layer in Fig. 1. The absolute orientation of the long axis of the molecules is observed to be parallel to the near-neighbor directions of the Pt(111) lattice. The sketch of the observed features, shown in Fig. 2, with the molecules overlayed arbitrarily onto on-top sites of a Pt(111) lattice, demonstrates that the molecules are located on 3x3 lattice sites, with separation of 4 lattice constants between domains. Although the (6x3) LEED pattern reported previously was reproduced, the proposed unit cell is seldom observed in the STM images.

Resolution in the scanning tunneling microscope

1991 ◽  
Vol 49 ◽  
pp. 488-489
Author(s):  
R. J. Wilson ◽  
D. D. Chambliss ◽  
S. Chiang ◽  
V. M. Hallmark
Keyword(s):  
Scanning Tunneling Microscope ◽  
Fundamental Principle ◽  
Atomic Scale ◽  
Lateral Resolution ◽  
Scanning Tunneling ◽  
Electronic Noise ◽  
Vertical Resolution ◽  
Tunneling Microscopy ◽  
Spatial Profile ◽  
Theoretical Analyses

Scanning tunneling microscopy (STM) has been used for many atomic scale observations of metal and semiconductor surfaces. The fundamental principle of the microscope involves the tunneling of evanescent electrons through a 10Å gap between a sharp tip and a reasonably conductive sample at energies in the eV range. Lateral and vertical resolution are used to define the minimum detectable width and height of observed features. Theoretical analyses first discussed lateral resolution in idealized cases, and recent work includes more general considerations. In all cases it is concluded that lateral resolution in STM depends upon the spatial profile of electronic states of both the sample and tip at energies near the Fermi level. Vertical resolution is typically limited by mechanical and electronic noise.

Scanning tunneling microscopy of E. coli RNA polymerase deposited onto an Au substrate by an electrochemical process

1991 ◽  
Vol 49 ◽  
pp. 378-379
Author(s):  
Rebecca W. Keller ◽  
Carlos Bustamante ◽  
David Bear
Keyword(s):  
Scanning Tunneling Microscope ◽  
Biological Sample ◽  
Substrate Surface ◽  
Electrochemical Process ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Tunneling Microscope ◽  
E Coli ◽  
Preparation Techniques

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.

scholarly journals Resolving Complex Atomic-Scale Spin Structures by Spin-Polarized Scanning Tunneling Microscopy

2001 ◽  
Vol 86 (18) ◽  
pp. 4132-4135 ◽  
Author(s):  
D. Wortmann ◽  
S. Heinze ◽  
Ph. Kurz ◽  
G. Bihlmayer ◽  
S. Blügel
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Spin Structures ◽  
Spin Polarized
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