JVB Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue

Jul 2013

Volume 31, Issue 4 (partial)

back to top
RSS Feeds

Evolution of Physics and Chemistry of Surfaces and Interfaces: A Perspective of the Last 40 Years

David K. Ferry

J. Vac. Sci. Technol. B 31, 048501 (2013); http://dx.doi.org/10.1116/1.4806761 (6 pages)

Online Publication Date: 17 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Physics and Chemistry of Surfaces and Interfaces conference has maintained a focus on the interfacial and surface properties of materials since its initiation in 1974. The conference continues to be a major force in this field, bringing together scientists from a variety of disciplines to focus upon the science of interfaces and surfaces. Here, a historical view of the development of the conference and a discussion of some of the themes that have been focal points for many years are presented.
Show PACS
01.30.Ww Editorials
01.65.+g History of science
73.20.At Surface states, band structure, electron density of states
68.35.Ct Interface structure and roughness
68.35.bg Semiconductors
back to top
RSS Feeds

Atomic-scale movement induced in nanoridges by scanning tunneling microscopy on epitaxial graphene grown on 4H-SiC(0001)

Peng Xu, Steven D. Barber, J. Kevin Schoelz, Matthew L. Ackerman, Dejun Qi, Paul M. Thibado, Virginia D. Wheeler, Luke O. Nyakiti, Rachael L. Myers-Ward, Charles R. Eddy, Jr., and D. Kurt Gaskill

J. Vac. Sci. Technol. B 31, 04D101 (2013); http://dx.doi.org/10.1116/1.4803137 (5 pages)

Online Publication Date: 1 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanoscale ridges in epitaxial multilayer graphene grown on the silicon face of 4° off-cut 4H-SiC (0001) were found using scanning tunneling microscopy (STM). These nanoridges are only 0.1 nm high and 25–50 nm wide, making them much smaller than previously reported ridges. Atomic-resolution STM was performed near and on top of the nanoridges using a dual scanning technique in which forward and reverse images are simultaneously recorded. An apparent 100% enlarged graphene lattice constant is observed along the leading edge of the image for both directions. Horizontal movement of the graphene, due to both an electrostatic attraction to the STM tip and weak bonding to the substrate, is thought to contribute to the results.
Show PACS
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
61.48.Gh Structure of graphene
61.46.-w Structure of nanoscale materials

Tuning the electronic states of individual Co acceptors in GaAs

Anne L. Benjamin, Donghun Lee, and Jay A. Gupta

J. Vac. Sci. Technol. B 31, 04D102 (2013); http://dx.doi.org/10.1116/1.4803841 (4 pages)

Online Publication Date: 7 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Scanning tunneling microscope studies of individual impurities in semiconductors explore challenges associated with future nanoscale electronics and can provide insight into how new materials properties such as ferromagnetic ordering arise from impurity interactions. Atomic manipulation and tunneling spectroscopy were employed to characterize and control the acceptor states of Co atoms substituted for Ga in the GaAs(110) surface. Three states were observed whose appearance in tunneling spectra was sensitive to the tip position within the acceptor complex. The energy of these states did not follow bending of the host bands due to the tip-induced electric field, but did respond to the Coulomb potential of nearby charged defects, such as As vacancies. By applying voltage pulses with the scanning tunneling microscope tip, the vacancies could be positioned on the surface, thus enabling tunable control over the Co acceptor states.
Show PACS
73.20.Hb Impurity and defect levels; energy states of adsorbed species
61.72.S- Impurities in crystals
61.72.Yx Interaction between different crystal defects; gettering effect
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)

Role of bias voltage and tunneling current in the perpendicular displacements of freestanding graphene via scanning tunneling microscopy

Peng Xu, Steven D. Barber, Matthew L. Ackerman, James Kevin Schoelz, and Paul M. Thibado

J. Vac. Sci. Technol. B 31, 04D103 (2013); http://dx.doi.org/10.1116/1.4804401 (5 pages)

Online Publication Date: 10 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Systematic displacement measurements of freestanding graphene as a function of applied bias voltage and tunneling current setpoint using scanning tunneling microscopy (STM) are presented. When the bias voltage is increased, the graphene approaches the STM tip, while, on the other hand, when the tunneling current is increased the graphene contracts from the STM tip. To understand the role of the bias voltage, the authors quantitatively model the attractive force between the tip and the sample using electrostatics. For the tunneling current, they qualitatively model the contraction of the graphene using entropic concepts. These complementary results enhance the understanding of each other and highlight peculiarities of the system.
Show PACS
73.40.Gk Tunneling
72.80.Vp Electronic transport in graphene
81.05.ue Graphene

Ballistic phonon thermal conductance in graphene nanoribbons

Hiroki Tomita and Jun Nakamura

J. Vac. Sci. Technol. B 31, 04D104 (2013); http://dx.doi.org/10.1116/1.4804617 (7 pages)

Online Publication Date: 14 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Phonon dispersions for graphene nanoribbons (GNRs) have been derived from the first-principles calculations, and ballistic phonon thermal conductances have been evaluated using the Landauer theory. The phonon thermal conductance per unit width for GNR is larger than that for graphene and increases with decreasing ribbon width. The normalized thermal conductance with a unit of thermal quantum for the zigzag GNR is higher than that for the single-walled carbon nanotube that has a circumferential length corresponding to the width of GNR.
Show PACS
66.70.-f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves
63.22.Rc Phonons in graphene
63.20.D- Phonon states and bands, normal modes, and phonon dispersion
71.20.Tx Fullerenes and related materials; intercalation compounds
71.15.-m Methods of electronic structure calculations
73.23.Ad Ballistic transport

Integrating MBE materials with graphene to induce novel spin-based phenomena

Adrian G. Swartz, Kathleen M. McCreary, Wei Han, Jared J. I. Wong, Patrick M. Odenthal, Hua Wen, Jen-Ru Chen, Roland K. Kawakami, Yufeng Hao, Rodney S. Ruoff, and Jaroslav Fabian

J. Vac. Sci. Technol. B 31, 04D105 (2013); http://dx.doi.org/10.1116/1.4803843 (8 pages)

Online Publication Date: 15 May 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Magnetism in graphene is an emerging field that has received much theoretical attention. In particular, there have been exciting predictions for induced magnetism through proximity to a ferromagnetic insulator as well as through localized dopants and defects. Here, the authors discuss their experimental work using molecular beam epitaxy to modify the surface of graphene and induce novel spin-dependent phenomena. First, they investigate the epitaxial growth of the ferromagnetic insulator EuO on graphene and discuss possible scenarios for realizing exchange splitting and exchange fields by ferromagnetic insulators. Second, they investigate the properties of magnetic moments in graphene originating from localized pz-orbital defects (i.e., adsorbed hydrogen atoms). The behavior of these magnetic moments is studied using nonlocal spin transport to directly probe the spin-degree of freedom of the defect-induced states. They also report the presence of enhanced electron g-factors caused by the exchange fields present in the system. Importantly, the exchange field is found to be highly gate dependent, with decreasing g-factors with increasing carrier densities.
Show PACS
75.76.+j Spin transport effects
72.25.-b Spin polarized transport
71.70.Gm Exchange interactions
75.30.Et Exchange and superexchange interactions
75.30.Cr Saturation moments and magnetic susceptibilities
71.70.-d Level splitting and interactions
Close

© 2013 AVS Science & Technology of Materials, Interfaces, and Processing Help | Contact
close