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.

IN-SITU HIGH-TEMPERATURE SCANNING-TUNNELING-MICROSCOPY STUDIES OF TWO-DIMENSIONAL ISLAND-DECAY KINETICS ON ATOMICALLY SMOOTH TiN(001)

2000 ◽  
Vol 07 (05n06) ◽  
pp. 589-593 ◽  
Author(s):  
S. KODAMBAKA ◽  
V. PETROVA ◽  
A. VAILIONIS ◽  
P. DESJARDINS ◽  
D. G. CAHILL ◽  
...  
Keyword(s):  
High Temperature ◽  
Scanning Tunneling Microscopy ◽  
Ostwald Ripening ◽  
Single Atom ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Decay Kinetics ◽  
Tunneling Microscopy ◽  
Temperature Scanning

In-situ high-temperature scanning tunneling microscopy was used to follow the coarsening (Ostwald ripening) and decay kinetics of single and multiple two-dimensional TiN islands on atomically flat TiN (001) terraces and in single-atom deep vacancy pits at temperatures of 750–950°C. The rate-limiting mechanism for island decay was found to be surface diffusion rather than adatom attachment/detachment at island edges. We have modeled island-decay kinetics based upon the Gibbs–Thomson and steady state diffusion equations to obtain a step-edge energy per unit length of 0.23±0.05 eV/Å and an activation energy for adatom formation and diffusion of 3.4±0.3 eV.

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

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.

Relaxation of Nanostructures on the Si(111)(7×7) Surface by High Temperature Scanning Tunneling Microscopy

1998 ◽  
Vol 05 (03n04) ◽  
pp. 821-832 ◽  
Author(s):  
Ayahiko Ichimiya ◽  
Yoriko Tanaka ◽  
Kazuhiko Hayashi
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Three Dimensional ◽  
Thermal Relaxation ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscopy ◽  
Temperature Variable ◽  
Long Lifetime ◽  
Temperature Scanning ◽  
Silicon Islands

Single silicon islands have been produced on the Si(111)(7 × 7) surface by a scanning tunneling microscope (STM) tip. Thermal relaxation of the isolated islands is observed by temperature variable scanning tunneling microscopy with strong tip effects. The sizes of islands depend on time t with a functional form of (t0-t)α. It is found that α≃2/3 for single bilayer islands, and α≃1 for three-dimensional ones. During the decomposition of three-dimensional islands, step bunching of over-layers takes place, while the islands have certain facets, like a pyramid just after the creation. At the final stages of the three-dimensional island decompositions, two-dimensional ones with 5 × 5 structure always appear. We have found that characteristic 5 × 5 islands with a long lifetime are formed during relaxation, but the 7 × 7 islands have mostlt a short lifetime. Rotation of small islands is also observed during relaxation. We discuss the results in terms of two-dimensional vapor phase processes.

STM STUDIES OF ELECTRONIC ORDER IN THE UNDERDOPED SURFACE OF YBa2Cu3Oy

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3199-3201
Author(s):  
TERUKAZU NISHIZAKI ◽  
NORIO KOBAYASHI ◽  
MAKOTO MAKI
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling ◽  
Long Range Order ◽  
Tunneling Microscopy ◽  
One Dimensional ◽  
Stm Image ◽  
Temperature Scanning ◽  
The One ◽  
Carrier Doping ◽  
Electronic Order

To study the nanoscale electronic order in high-T c superconductors, we have performed low-temperature scanning tunneling microscopy (STM) experiments on YBa 2 Cu 3 O y, single crystals. The electronic state of the underdoped CuO 2 plane is studied through the BaO surface taking advantage of the cleaved surface, which has an insufficient carrier doping into the topmost CuO 2 plane because of the incomplete carrier reservoir. The STM image measured at low bias-voltage below 20 mV shows the one-dimensional (1D) electronic modulation along the Cu - O bonds. The 1D modulation do not have long-range order and the periodicity varies within the range ~ 2a - 4a depending on the position on the surface. These results indicate that electronic order in underdoped YBa 2 Cu 3 O y, differs from the 4a×4a checkerboard structure observed in Bi 2 Sr 2 CaCu 2 O y and Ca 2-x Na x CuO 2 Cl 2.

scholarly journals Realizing Two-Dimensional Spin Arrays on Surfaces via Halogen-Bonding Molecular Self-Assembly

2021 ◽  
Author(s):  
Dingguan Wang ◽  
Zishen Wang ◽  
Shaofei Wu ◽  
Arramel Arramel ◽  
Xinmao Yin ◽  
...  
Keyword(s):  
Single Molecule ◽  
Self Assembly ◽  
Halogen Bonding ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Halogen Bonds ◽  
Tunneling Microscopy ◽  
Single Molecule Level ◽  
Magnetic Devices ◽  
Temperature Scanning

Well-ordered spin arrays are highly desirable for next-generation molecule-based magnetic devices, and yet its synthetic method remains a challenging task. Herein, we demonstrate the realization of two-dimensional supramolecular spin arrays on surfaces via halogen-bonding molecular self-assembly. A bromine-terminal perchlorotriphenymethyl radical with net carbon spin was synthesized and deposited on Au(111) to achieve two-dimensional supramolecular spin arrays. By taking advantage of the diversity of halogen bonds, five supramolecular spin arrays are presented with ultrahigh spin densities (up to the value of 3 × 10<sup>13</sup> spins at the size of a flash drive), as probed by low-temperature scanning tunneling microscopy at the single-molecule level. First principle calculations verify that the formation of three distinct types of halogen bonds can be used to tailor supramolecular phases via molecular coverage and annealing temperature. Our work demonstrates supramolecular self-assembly as a promising method to engineering 2D spin arrays for potential application in magnetic devices.

scholarly journals Temperature-Dependent Accommodation of Two Lattices of Largely Different Size during Growth

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 710
Author(s):  
Carsten Sprodowski ◽  
Karina Morgenstern
Keyword(s):  
Low Temperature ◽  
Variable Temperature ◽  
Lattice Misfit ◽  
Scanning Tunneling ◽  
Temperature Structure ◽  
Misfit Dislocations ◽  
Tunneling Microscopy ◽  
Large Lattice ◽  
Higher Temperature ◽  
Temperature Scanning

If a material grows on another material with a largely different lattice constant, which of the two adapts for an energetically favorable growth? To tackle this question, we investigate the growth of Ag on Cu(111) by variable temperature scanning tunneling microscopy. The structures grown between 120 and 170 K are remarkably different from those grown between 200 and 340 K. The low-temperature structure is rectangular-like and consists of stacked rods, 7 to 8 Ag atoms long, which form a superstructure without long-range order. This structure covers the whole surface prior to nucleation of further layers. The high-temperature structure is hexagonal and consists of misfit dislocations forming 8 × 8 to 10 × 10 superstructures. For this structure, second layer nucleation sets in far before the closure of the first monolayer. While both structures are driven by the large lattice misfit between the two materials, the growing Ag layer adapts to the Cu surface at low temperature, while the Cu surface adapts to the growing Ag layer at higher temperature.

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