Mapping of local electronic properties in nanostructured CMR thin films by Scanning Tunneling Microscopy (STM) and Local Conductance Map (LCMAP)

2004 ◽  
Vol 838 ◽  
Author(s):  
Sohini Kar ◽  
Barnali Ghosh ◽  
L. K. Brar ◽  
M A. Paranjape ◽  
A. K. Raychaudhuri
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Grain Boundaries ◽  
Electronic Properties ◽  
Variable Temperature ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Colossal Magnetoresistive ◽  
Spatially Resolved ◽  
Temperature Scanning

ABSTRACTWe have investigated the local electronic properties and the spatially resolved magnetoresistance of a nanostructured film of a colossal magnetoresistive (CMR) material by local conductance mapping (LCMAP) using a variable temperature Scanning Tunneling Microscope (STM) operating in a magnetic field. The nanostructured thin films (thickness ≈500nm) of the CMR material La0.67Sr0.33MnO3(LSMO) on quartz substrates were prepared using chemical solution deposition (CSD) process. The CSD grown films were imaged by both STM and atomic force microscopy (AFM). Due to the presence of a large number of grain boundaries (GB's), these films show low field magnetoresistance (LFMR) which increases at lower temperatures.The measurement of spatially resolved electronic properties reveal the extent of variation of the density of states (DOS) at and close to the Fermi level (EF) across the grain boundaries and its role in the electrical resistance of the GB. Measurement of the local conductance maps (LCMAP) as a function of magnetic field as well as temperature reveals that the LFMR occurs at the GB. While it was known that LFMR in CMR films originates from the GB, this is the first investigation that maps the local electronic properties at a GB in a magnetic field and traces the origin of LFMR at the GB.

scholarly journals Strain-Relief Patterns and Kagome Lattice in Self-Assembled C60 Thin Films Grown on Cd(0001)

2021 ◽  
Vol 22 (13) ◽  
pp. 6880
Author(s):  
Zilong Wang ◽  
Minlong Tao ◽  
Daxiao Yang ◽  
Zuo Li ◽  
Mingxia Shi ◽  
...  
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Kagome Lattice ◽  
Tunneling Microscopy ◽  
Kagomé Lattice ◽  
Temperature Scanning ◽  
C60 Films

We report an ultra-high vacuum low-temperature scanning tunneling microscopy (STM) study of the C60 monolayer grown on Cd(0001). Individual C60 molecules adsorbed on Cd(0001) may exhibit a bright or dim contrast in STM images. When deposited at low temperatures close to 100 K, C60 thin films present a curved structure to release strain due to dominant molecule–substrate interactions. Moreover, edge dislocation appears when two different wavy structures encounter each other, which has seldomly been observed in molecular self-assembly. When growth temperature rose, we found two forms of symmetric kagome lattice superstructures, 2 × 2 and 4 × 4, at room temperature (RT) and 310 K, respectively. The results provide new insight into the growth behavior of C60 films.

scholarly journals Orientation Ordering and Chiral Superstructures in Fullerene Monolayer on Cd (0001)

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1305
Author(s):  
Yuzhi Shang ◽  
Zilong Wang ◽  
Daxiao Yang ◽  
Yaru Wang ◽  
Chaoke Ma ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Orientational Disorder ◽  
Temperature Scanning ◽  
Orientation Ordering ◽  
The Individual ◽  
Misorientation Angles

The structure of C60 thin films grown on Cd (0001) surface has been investigated from submonolayer to second monolayer regimes with a low-temperature scanning tunneling microscopy (STM). There are different C60 domains with various misorientation angles relative to the lattice directions of Cd (0001). In the (2√3 × 2√3) R30° domain, orientational disorder of the individual C60 molecules with either pentagon, hexagon, or 6:6 bond facing up has been observed. However, orientation ordering appeared in the R26° domain such that all the C60 molecules adopt the same orientation with the 6:6 bond facing up. In particular, complex chiral motifs composed of seven C60 molecules with clockwise or anticlockwise handedness have been observed in the R4° and R8° domains, respectively. Scanning tunneling spectroscopy (STS) measurements reveal a reduced HOMO–LOMO gap of 2.1 eV for the C60 molecules adsorbed on Cd (0001) due to the substrate screening and charge transfer from Cd to C60 molecules.

In Situ Variable-Temperature Scanning Tunneling Microscopy Studies of Graphene Growth Using Benzene on Pd(111)

ACS Nano ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1141-1147 ◽  
Author(s):  
Pedro Arias ◽  
Jan Tesař ◽  
Abby Kavner ◽  
Tomáš Šikola ◽  
Suneel Kodambaka
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Variable Temperature ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Graphene Growth ◽  
Temperature Scanning

Local Electronic Properties in the Presence of Internal and External Magnetic Fields Studied by Variable-Temperature Scanning Tunneling Spectroscopy

1998 ◽  
Vol 37 (Part 1, No. 6B) ◽  
pp. 3769-3773 ◽  
Author(s):  
Roland Wiesendanger ◽  
Matthias Bode ◽  
Ralph Dombrowski ◽  
Mathias Getzlaff ◽  
Markus Morgenstern ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Electronic Properties ◽  
Variable Temperature ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Temperature Scanning

Identifying the electronic properties of the Ge(111)-(2×1) surface by low-temperature scanning tunneling microscopy

JETP Letters ◽  
2005 ◽  
Vol 82 (5) ◽  
pp. 279-283 ◽  
Author(s):  
P. I. Arseyev ◽  
N. S. Maslova ◽  
V. I. Panov ◽  
S. V. Savinov ◽  
C. Van Haesendonck
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
Electronic Properties ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Temperature Scanning

Island decay on the anisotropic Ag(110) surface

2000 ◽  
Vol 648 ◽  
Author(s):  
Karina Morgenstern ◽  
Erik Lægsgaard ◽  
Flemming Besenbacher
Keyword(s):  
Decay Mode ◽  
Ostwald Ripening ◽  
Variable Temperature ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscopy ◽  
Sharp Transition ◽  
One Dimensional ◽  
Temperature Scanning ◽  
Rate Limiting

AbstractWe have investigated the decay of two-dimensional islands on the anisotropic Ag(110) surface using variable-temperature scanning tunneling microscopy. Contrary to predictions from traditional Ostwald ripening theory, a quasi-one-dimensional decay mode is observed at low temperatures (175-220 K). A surprisingly sharp transition to the quasi-two-dimensional decay mode is observed around 220 K. This transition is accompanied by a fast equilibration of the island shape. These findings have tentatively been rationalized within a simple model to identify the underlying rate limiting atomistic processes.

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