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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

20 Feb 2012

Volume 100, Issue 8, Articles (08xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 100, 082401 (2012); http://dx.doi.org/10.1063/1.3684972 (4 pages)

Elizabeth Rapoport and Geoffrey S. D. Beach
Enlarge Image | Read More
Page 2 of 4 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Coupling resistance between n-type surface accumulation layer and p-type bulk in InN:Mg thin films

Christophe A. Hurni, Soojeong Choi, Oliver Bierwagen, and James S. Speck

Appl. Phys. Lett. 100, 082106 (2012); http://dx.doi.org/10.1063/1.3680102 (4 pages) | Cited 3 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Indium nitride is the least studied of the III-nitride though it has great potential due to its small bandgap of 0.65 eV and a small effective electron mass. InN:Mg was recently confirmed to be p-type. However, Hall measurements on InN:Mg still show n-type conductivity, even when InN:Mg is very thick. Some studies have suggested the possibility of a high coupling resistance between the surface electron accumulation and the bulk p-InN. In this study, we show through vertical and transmission-line model measurement that this coupling resistance is small and should not affect conductivity and Hall measurements.
Show PACS
73.61.Ey III-V semiconductors
68.55.ag Semiconductors
71.20.Nr Semiconductor compounds
81.05.Ea III-V semiconductors

Thermoelectric properties and structural variations in Bi2Te3−xSx crystals

W. Wong-Ng, H. Joress, J. Martin, P. Y. Zavalij, Y. Yan, and J. Yang

Appl. Phys. Lett. 100, 082107 (2012); http://dx.doi.org/10.1063/1.3688485 (4 pages) | Cited 2 times

Online Publication Date: 23 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the application of a custom-designed, non-destructive Seebeck coefficient screening technique, in combination with x-ray diffraction and Hall measurements, to characterize the effect of S substitution on n-type Bi2Te3−xSx single crystals. The results elucidate the detailed distribution of Te/S in the Bi2Te3−xSx crystals, including the preferred substitution site, to correlate the compositional gradient with the transport properties in different locations on the same crystal. As the S substitution increases, the carrier concentration increases, and the absolute Seebeck coefficient decreases. The observed trends in the transport properties and the compositional variations are consistent with a narrow gap semiconductor model.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
72.20.My Galvanomagnetic and other magnetotransport effects
61.66.Fn Inorganic compounds

Thermal conductivity of 1.3 μm InAs/GaAs quantum dot laser active material from chirp and 3ω measurements

Zhongyang Ge, Patricia Moat, Jing Xie, Junjie Hu, Jia-Sheng Huang, Xinyu Sun, Neinyi Li, B. E. White, Jr., and David Klotzkin

Appl. Phys. Lett. 100, 082108 (2012); http://dx.doi.org/10.1063/1.3687160 (4 pages)

Online Publication Date: 23 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Semiconductor quantum dots have very low thermal conductivities compared with bulk materials or quantum well structures. In this paper, thermal conductivity of InAs quantum dot laser active regions was determined using two different approaches. Measured conductivity is between 0.03 and 0.05 W/(m-K) for both approaches, in reasonable agreement considering the approximations used in the measurement method. This reduced thermal conductivity of the active region in quantum dot lasers has a significant effect on the laser operating characteristics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems

Phonon spectrum and bonding properties of Bi2Se3: Role of strong spin-orbit interaction

Bao-Tian Wang and Ping Zhang

Appl. Phys. Lett. 100, 082109 (2012); http://dx.doi.org/10.1063/1.3689759 (4 pages) | Cited 4 times

Online Publication Date: 23 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Phonon dispersions of one typical three-dimensional topological insulator Bi2Se3 have been studied within density functional theory. The soft modes of two acoustic branches along the Z – F and Γ-F directions within the pure local density approximation will transit to show imaginary frequency oscillating after including the spin-orbit interaction (SOI). Similar phenomenon has also been observed for Bi2Te3. Besides, we have found that the weak van der Waals forces between two Se1 layers in Bi2Se3 are strengthened by turning on the spin-orbit interaction.
Show PACS
63.20.D- Phonon states and bands, normal modes, and phonon dispersion
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
71.20.Ps Other inorganic compounds
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect

Interface nature of oxidized single-crystal arrays of etched Si nanowires on (100)Si

M. Jivanescu, A. Stesmans, R. Kurstjens, and F. Dross

Appl. Phys. Lett. 100, 082110 (2012); http://dx.doi.org/10.1063/1.3682315 (4 pages) | Cited 2 times

Online Publication Date: 23 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Low temperature electron spin resonance studies have been carried out on single crystalline arrays of sub-10 nm Si nanowires (NWs) manufactured on (100)Si by top down etching and oxidation thinning. This reveals the presence of a substantial inherent density of Pb0 (Si3 ≡ Si•) defects (traps) at the NW Si/SiO2 interfaces, due to particular faceting and enhanced interface strain, leaving NW interfaces of reduced electrical quality. Perusal of the specific properties of the occurring Pb-type defect system points to a nanopillar morphology compatible with NWs predominantly bordered by {110} facets, with cross sectional shape of 〈100〉 truncated {110} squares. The inherent interface quality appears limited by the wire-narrowing thermal oxidation procedure.
Show PACS
81.65.Cf Surface cleaning, etching, patterning
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
76.30.Mi Color centers and other defects
61.72.J- Point defects and defect clusters

Measuring the concentration and energy distribution of interface states using a non-contact corona oxide semiconductor method

J. E. de Vries and Y. Rosenwaks

Appl. Phys. Lett. 100, 082111 (2012); http://dx.doi.org/10.1063/1.3689004 (3 pages) | Cited 1 time

Online Publication Date: 24 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electronic states distribution at the Si-SiO2 interface was measured by combining contactless corona charge-voltage measurement and low-frequency capacitance voltage method. Using device equivalent circuit modeling, we were able to obtain the silicon-insulator interface states energy distribution across the whole Si band gap with a single measurement. The measured distribution has the well known u-shaped curve, with a minimum around mid gap of 2 × 1010 cm−2 eV−1 and maximum values close to the band edges reaching 6 × 1013 cm−2 eV−1. Two distinct peaks were observed at 0.21 eV and 0.88 eV above the valence band maximum which correspond to the Si (100) Pb0 centers.
Show PACS
73.20.At Surface states, band structure, electron density of states
71.20.Mq Elemental semiconductors

Comparison of thermal and atomic-layer-deposited oxides on 4H-SiC after post-oxidation-annealing in nitric oxide

Changhyun Kim, Jeong Hyun Moon, Jeong Hyuk Yim, Do Hyun Lee, Jong Ho Lee, Hun Hee Lee, and Hyeong Joon Kim

Appl. Phys. Lett. 100, 082112 (2012); http://dx.doi.org/10.1063/1.3689766 (4 pages) | Cited 1 time

Online Publication Date: 24 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electrical properties of thermally grown and atomic-layer-deposition (ALD) oxides, followed by nitridation treatment, on 4H-SiC substrate were compared. The nitridation treatment was performed with post oxidation annealing in NO atmosphere (NO POA). The best electrical characteristics of the thermally grown and ALD oxides were observed at 120 and 180 min NO POA, respectively. The NO POA treated ALD oxide showed extremely low interface trap density (Dit), less than 1011 eV−1 cm−1. A metal-oxide-semiconductor field-effect-transistor with the ALD oxide showed high field effect mobility, especially in the high electric field region. The reasons for these superior results were also discussed.
Show PACS
81.20.-n Methods of materials synthesis and materials processing
81.40.Gh Other heat and thermomechanical treatments
81.65.Mq Oxidation
back to top
RSS Feeds

Dynamics of superparamagnetic microbead transport along magnetic nanotracks by magnetic domain walls

Elizabeth Rapoport and Geoffrey S. D. Beach

Appl. Phys. Lett. 100, 082401 (2012); http://dx.doi.org/10.1063/1.3684972 (4 pages) | Cited 7 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. Experiments show that nanotrack-guided domain walls can propel individual trapped beads through an aqueous medium at speeds approaching 1000 μm/s, 10 to 100 times faster than through any previously demonstrated mechanism.
Show PACS
75.20.-g Diamagnetism, paramagnetism, and superparamagnetism
75.75.-c Magnetic properties of nanostructures
75.60.Ch Domain walls and domain structure
75.50.Tt Fine-particle systems; nanocrystalline materials

Sub-nanosecond switching of vortex cores using a resonant perpendicular magnetic field

Ruifang Wang and Xinwei Dong

Appl. Phys. Lett. 100, 082402 (2012); http://dx.doi.org/10.1063/1.3687909 (3 pages) | Cited 2 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

multimedia

Show Abstract
We performed micromagnetic numerical studies on ultrafast switching of magnetic vortex cores (VCs) using a perpendicular magnetic field that oscillates at the eigenfrequency of a permalloy nanodisk. Our calculations show that a resonant magnetic field with amplitude of 30 mT stimulates strong axially symmetric magnetization oscillation and forces the vortex core to stay at the center of the nanodisk. The compression of the vortex core by spin wave leads to core reversal at 602 ps. This switching process is mediated by the propagation of a Neel wall across the sample thickness.
Show PACS
75.75.-c Magnetic properties of nanostructures
75.30.Ds Spin waves

Structure and magnetotransport properties of epitaxial nanocomposite La0.67Ca0.33MnO3:SrTiO3 thin films grown by a chemical solution approach

Ling Fei, Leyi Zhu, Xuemei Cheng, Haiyan Wang, Stacy M. Baber, Joshua Hill, Qianglu Lin, Yun Xu, Shuguang Deng, and Hongmei Luo

Appl. Phys. Lett. 100, 082403 (2012); http://dx.doi.org/10.1063/1.3688048 (5 pages) | Cited 7 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial La0.67Ca0.33MnO3:SrTiO3 (LCMO:STO) composite thin films have been grown on single crystal LaAlO3(001) substrates by a cost effective polymer-assisted deposition method. Both x-ray diffraction and high-resolution transmission electron microscopy confirm the growth of epitaxial films with an epitaxial relationship between the films and the substrates as (002)film||(002)sub and [202]film||[202]sub. The transport property measurement shows that the STO phase significantly increases the resistivity and enhances the magnetoresistance (MR) effect of LCMO and moves the metal-insulator transition to lower temperatures. For example, the MR values measured at magnetic fields of 0 and 3 T are −44.6% at 255 K for LCMO, −94.2% at 125 K for LCMO:3% STO, and −99.4% at 100 K for LCMO:5% STO, respectively.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Tt Fine-particle systems; nanocrystalline materials
75.75.-c Magnetic properties of nanostructures
72.20.My Galvanomagnetic and other magnetotransport effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
71.30.+h Metal-insulator transitions and other electronic transitions

Ferromagnetism in thin-film Cr-doped topological insulator Bi2Se3

P. P. J. Haazen, J.-B. Laloë, T. J. Nummy, H. J. M. Swagten, P. Jarillo-Herrero, D. Heiman, and J. S. Moodera

Appl. Phys. Lett. 100, 082404 (2012); http://dx.doi.org/10.1063/1.3688043 (3 pages) | Cited 9 times

Online Publication Date: 23 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the observation of ferromagnetism in epitaxial thin films of the topological insulator compound Bi2Se3 with chromium doping. The structural, magnetic, and magnetoelectrical properties of Bi2Se3 were investigated for Cr concentrations up to 10%. For a Cr content up to ∼5% the films are of good crystalline quality, with the lattice parameter a decreasing and the lattice parameter c increasing with increasing Cr concentration. The Curie temperature reached a maximum TC = 20 K for 5.2% Cr. Well-defined ferromagnetic hysteresis in the magnetization and in the magnetoresistance was also observed in these films.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
77.55.Nv Multiferroic/magnetoelectric films
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
72.20.My Galvanomagnetic and other magnetotransport effects
75.50.Dd Nonmetallic ferromagnetic materials

Direct detection of magnon spin transport by the inverse spin Hall effect

A. V. Chumak, A. A. Serga, M. B. Jungfleisch, R. Neb, D. A. Bozhko, V. S. Tiberkevich, and B. Hillebrands

Appl. Phys. Lett. 100, 082405 (2012); http://dx.doi.org/10.1063/1.3689787 (3 pages) | Cited 5 times

Online Publication Date: 24 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Conversion of traveling magnons into an electron carried spin current is demonstrated in a time resolved experiment using a spatially separated inductive spin-wave source and an inverse spin Hall effect (ISHE) detector. A spin-wave packet is excited in a yttrium-iron garnet waveguide by a microwave signal and is detected 3 mm apart by an attached platinum layer as a delayed ISHE voltage pulse. The delay appears due to the finite spin-wave group velocity and proves the magnon spin transport. The experiment suggests the utilization of spin waves for the information transfer over macroscopic distances in spintronic devices and circuits.
Show PACS
75.30.Ds Spin waves
75.50.Gg Ferrimagnetics
72.20.My Galvanomagnetic and other magnetotransport effects
72.25.-b Spin polarized transport
back to top
RSS Feeds

Strong vortex pinning in FeSe0.5Te0.5 epitaxial thin film

E. Bellingeri, S. Kawale, I. Pallecchi, A. Gerbi, R. Buzio, V. Braccini, A. Palenzona, M. Putti, M. Adamo, E. Sarnelli, and C. Ferdeghini

Appl. Phys. Lett. 100, 082601 (2012); http://dx.doi.org/10.1063/1.3688918 (4 pages) | Cited 3 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the magnetic field and angular dependence of the critical current density of epitaxial FeTe0.5Se0.5 thin films. The films exhibit high critical current values and weak dependence on the applied magnetic field. The Jc is larger for field parallel to the c-axis, which is the opposite behavior of what expected from the critical field anisotropy. The analysis of the activation energy for vortex motion indicates that the single pinning regime holds up to 9 T, suggesting that correlated pinning centers are more effective than the vortex-vortex interaction even at the largest applied fields. Scanning tunneling microscope analysis indicates threading dislocations as possible pinning centers.
Show PACS
74.25.Wx Vortex pinning (includes mechanisms and flux creep)
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
74.25.Sv Critical currents
74.78.-w Superconducting films and low-dimensional structures
68.55.at Other materials

Reduced microwave loss in trenched superconducting coplanar waveguides

Michael R. Vissers, Jeffrey S. Kline, Jiansong Gao, David S. Wisbey, and David P. Pappas

Appl. Phys. Lett. 100, 082602 (2012); http://dx.doi.org/10.1063/1.3683552 (3 pages) | Cited 3 times

Online Publication Date: 24 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Reducing the contribution of all sources of microwave loss is important for increasing coherence times in superconducting qubits. In this paper we investigate reducing the loss by systematically removing Si substrate material from the gap region in titanium nitride coplanar waveguides fabricated on intrinsic Si substrates. By exploiting the radial dependence of the etch rate in a parallel plate reactive ion etcher, otherwise identical coplanar waveguides with only the Si gaps etched to varying depth, i.e., trenched, were created in a single TiN film within a single processing step. Measurements at these multiple depths permit the study of the loss reduction in isolation to the unintentional effects caused by any single processing step. When comparing the loss from all trench depths we found that the high power loss was similar, but in the single photon limit the loss was reduced by a factor of two for deeper trenches in agreement with predictions from finite element analysis.
Show PACS
85.25.-j Superconducting devices
84.40.Az Waveguides, transmission lines, striplines
02.70.Dh Finite-element and Galerkin methods
81.65.Cf Surface cleaning, etching, patterning
back to top
RSS Feeds

High dielectric tunability in lead niobate pyrochlore films

M. Mirsaneh, B. E. Hayden, E. Furman, S. Perini, M. T. Lanagan, and I. M. Reaney

Appl. Phys. Lett. 100, 082901 (2012); http://dx.doi.org/10.1063/1.3687722 (3 pages) | Cited 3 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High throughput physical vapor deposition has been used to grow crystalline PbnNb2O5+n (0.6 < n < 4.6) thin films on a single chip. Relative permittivity (ɛr) and dielectric loss (tan δ) were frequency independent between 100 Hz and 1 MHz and −60 °C–100 °C. Dielectric tunability achieved a maximum in the cubic pyrochlore phase (Pb1.2Nb2O6.2, PN, Pb ≈ 38%) of ∼26% (0.44 MV/cm). In comparison to barium strontium titanate (BST) and bismuth zinc niobate (BZN), PN exhibited attractive tan δ ∼ 0.0009 (0.013–0.005 in BST and 0.008–0.0005 in BZN), comparable or superior ɛr of 419 (450 in BST and 160–220 in BZN) and 26% tunability (∼50% in BST and 3.5% in BZN at equivalent fields). PN is thus considered an ideal candidate for tunable device applications.
Show PACS
77.55.-g Dielectric thin films
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
68.55.aj Insulators
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
77.22.Ch Permittivity (dielectric function)
77.22.Gm Dielectric loss and relaxation

Dielectric responses and scaling behaviors in Aurivillius Bi6Ti3Fe2O18 multiferroic thin films

W. Bai, G. Chen, J. Y. Zhu, J. Yang, T. Lin, X. J. Meng, X. D. Tang, C. G. Duan, and J. H. Chu

Appl. Phys. Lett. 100, 082902 (2012); http://dx.doi.org/10.1063/1.3688033 (4 pages) | Cited 5 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Dielectric responses and scaling behaviors of Aurivillius Bi6Ti3Fe2O18 (BTF2) multiferroic thin films were systemically detailed by the temperature-dependent dielectric/impedance spectroscopy. We clarified two dielectric relaxation processes presented in grain interior of the BTF2 films. One relaxation below ∼500 K was proposed to associate with the localized hopping process of carrier between Fe3+ and Fe2+ inside the grains. Another one above ∼500 K arose from the long-range movement of oxygen vacancies. The scaling behaviors implied that the distribution of relaxation times for oxygen vacancies was temperature independent while the dynamical processes for the hopping carriers presumably depended on temperature.
Show PACS
77.22.Gm Dielectric loss and relaxation
61.72.jd Vacancies
77.80.Dj Domain structure; hysteresis
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
75.85.+t Magnetoelectric effects, multiferroics
77.55.Nv Multiferroic/magnetoelectric films

Phase transition behaviors of PbZr1−xTixO3 single crystals as revealed by elastic anomalies and central peaks

Tae Hyun Kim, Jae-Hyeon Ko, Seiji Kojima, Alexei A. Bokov, Xifa Long, and Zuo-Guang Ye

Appl. Phys. Lett. 100, 082903 (2012); http://dx.doi.org/10.1063/1.3688050 (4 pages) | Cited 5 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Two PbZr1−xTixO3 (PZT) single crystals with x ≈ 0.45 and 0.42 near the morphotropic phase boundary were studied by Brillouin light scattering, giving rise to the first single-crystal elastic data which were discussed in terms of the correlation between the acoustic anomalies and the phase transition sequence. The ferroelectric phase transition of PZT with x ≈ 0.45 was second order (or very close to the second order) which accompanied very large polarization fluctuations resulting in the formation of strong central peaks. A revised phase diagram of PZT was suggested including refinement of the tilt phase boundary and a possible existence of tricritical point.
Show PACS
77.84.Cg PZT ceramics and other titanates
64.60.Kw Multicritical points
78.35.+c Brillouin and Rayleigh scattering; other light scattering
77.80.-e Ferroelectricity and antiferroelectricity

Stabilization of mixed-phase structures in highly strained BiFeO3 thin films via chemical-alloying

Anoop R. Damodaran, Eric Breckenfeld, Amber K. Choquette, and Lane W. Martin

Appl. Phys. Lett. 100, 082904 (2012); http://dx.doi.org/10.1063/1.3688175 (4 pages) | Cited 3 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Chemical-alloying is demonstrated to stabilize the mixed-phase structure of highly strained epitaxial BiFeO3/LaAlO3 (001) heterostructures. Such mixed-phase structures are essential for the large electromechanical responses (4%–5% strains under applied electric field); however, films with thickness exceeding 250 nm undergo an epitaxial breakdown to a non-epitaxial bulk-like rhombohedral-phase. Such an irreversible transformation of the mixed-phase structure limits the magnitude of the net surface displacement associated with these field-induced phase transformations. Using high-resolution x-ray diffraction reciprocal space mapping and scanning-probe-based studies, we show that chemical-alloying of BiFeO3 thin films can stabilize these mixed-phase structures and delay the onset of epitaxial breakdown.
Show PACS
68.55.aj Insulators
77.65.-j Piezoelectricity and electromechanical effects
77.22.Jp Dielectric breakdown and space-charge effects
75.50.Ee Antiferromagnetics
77.80.-e Ferroelectricity and antiferroelectricity
75.80.+q Magnetomechanical effects, magnetostriction

Insights into electrical characteristics of silicon doped hafnium oxide ferroelectric thin films

Dayu Zhou (周大雨), J. Müller, Jin Xu (徐进), S. Knebel, D. Bräuhaus, and U. Schröder

Appl. Phys. Lett. 100, 082905 (2012); http://dx.doi.org/10.1063/1.3688915 (4 pages)

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Silicon doped hafnium oxide thin films were recently discovered to exhibit ferroelectricity. In the present study, metal-ferroelectric-metal capacitors with Si:HfO2 thin films as ferroelectric material and TiN as electrodes have been characterized with respect to capacitance and current density as functions of temperature and applied voltage. Polarity asymmetry of the frequency dependent coercive field was explained by interfacial effects. No ferroelectric-paraelectric phase transition was observed at temperatures up to 478 K. Clear distinctions between current evolutions with or without polarization switching were correlated to the time competition between the measurement and the response of relaxation mechanisms.
Show PACS
77.55.fp Other ferroelectric films
73.61.Ng Insulators
77.22.Ej Polarization and depolarization
77.22.Gm Dielectric loss and relaxation
77.80.Fm Switching phenomena
back to top
RSS Feeds

Silicon intercalation at the interface of graphene and Ir(111)

Lei Meng, Rongting Wu, Haitao Zhou, Geng Li, Yi Zhang, Linfei Li, Yeliang Wang, and H.-J. Gao

Appl. Phys. Lett. 100, 083101 (2012); http://dx.doi.org/10.1063/1.3687688 (4 pages) | Cited 7 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the structural and electronic properties in the heterostructure of graphene/silicon/Ir(111). A (√19 × √19)R23.41° superstructure is confirmed by low energy electron diffraction and scanning tunneling microscopy and its formation is ascribed to silicon intercalation at the interface between the graphene and the Ir(111) substrate. The dI/dV measurements indicate that the interaction between graphene and Ir is effectively decoupled after silicon intercalation. Raman spectroscopy also reveals the vibrational states of graphene, G peak and 2D peak, which further demonstrates that the silicon-buffered graphene behaves more like intrinsic graphene.
Show PACS
73.40.-c Electronic transport in interface structures
68.35.Ct Interface structure and roughness
78.30.Na Fullerenes and related materials
63.20.-e Phonons in crystal lattices

Electronic structures of silicene fluoride and hydride

Yi Ding and Yanli Wang

Appl. Phys. Lett. 100, 083102 (2012); http://dx.doi.org/10.1063/1.3688035 (4 pages) | Cited 12 times

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Silicene is the graphene-like silicon nanosheet, which has been synthesized very recently [B. Lalmi, H. Oughaddou, H. Enriquez, A. Kara, S. Vizzini, B. Ealet, and B. Aufray, Appl. Phys. Lett. 97, 223109 (2010)]. Using first-principles calculations, we systematically investigate the structures and properties of fluorinated and hydrogenated silicene, the silicon analogues of graphane. Different from the carbon-counterpart, the fluorination prefers the conformation with a zigzag-line buckling, while the hydrogenation keeps the chair conformation similar to graphane. A direct band gap is opened in the silicene fluoride, and the gap values can be continuously modulated by the strain. While for the hydride, a strain-induced indirect-to-direct band gap transition is found.
Show PACS
71.20.Ps Other inorganic compounds
81.40.Lm Deformation, plasticity, and creep
62.20.mq Buckling

Pure optical and reversible optically driven nanowriting of azobenzene block copolymers

F. Tantussi, S. Menghetti, E. Caldi, F. Fuso, M. Allegrini, and G. Galli

Appl. Phys. Lett. 100, 083103 (2012); http://dx.doi.org/10.1063/1.3685716 (4 pages) | Cited 1 time

Online Publication Date: 21 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on pure optical nanowriting in the near-field of spin-coated films of a specifically synthesized azobenzene-containing block copolymer. Writing is accomplished by linear polarized blue laser radiation, which is efficiently absorbed by the material, and readout is based on polarization-modulation of red laser radiation, which is practically unabsorbed. Purely optical, stable, and reversible modifications are observed at the ∼100 nm scale. Remarkably, they are not accompanied by any observable topographical change. We attribute the result to the use of a small azobenzene content (3% mol) and to the block architecture of the material.
Show PACS
68.55.am Polymers and organics

Interface structure governed by plastic and structural dissimilarity in perovskite La0.7Sr0.3MnO3 nanodots on rock-salt MgO substrates

P. Abellán, J. Zabaleta, J. Santiso, M.-J. Casanove, N. Dix, J. Aguiar, N. D. Browning, N. Mestres, T. Puig, X. Obradors, and F. Sandiumenge

Appl. Phys. Lett. 100, 083104 (2012); http://dx.doi.org/10.1063/1.3687692 (4 pages)

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Self-assembled La0.7Sr0.3MnO3 perovskite nanodots have been grown on highly mismatched rock-salt type MgO substrates by chemical solution deposition. The interfacial dislocation structure indicates that the relaxation mechanism is governed by the easy glide of MgO 1/2〈101〉{101} dislocations towards the interface, where they dissociate into misfit-relieving and tilting components. The latter induce a 4-domain tilt pattern superimposed to the main cube-on-cube epitaxial orientation. It is shown that the inheritance of the rotational component of the Burgers vector has detrimental consequences on the interfacial quality, evidencing the impact of structural and plastic dissimilarity on the design of self-assembled nanostructures.
Show PACS
81.16.Dn Self-assembly
62.23.Eg Nanodots
68.35.Ct Interface structure and roughness
62.20.fq Plasticity and superplasticity
81.40.Lm Deformation, plasticity, and creep
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)

Guided filament formation in NiO-resistive random access memory by embedding gold nanoparticles

Mutsunori Uenuma, Bin Zheng, Kentaro Kawano, Masahiro Horita, Yasuaki Ishikawa, Ichiro Yamashita, and Yukiharu Uraoka

Appl. Phys. Lett. 100, 083105 (2012); http://dx.doi.org/10.1063/1.3688053 (3 pages) | Cited 2 times

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Controllable positioning of conductive filament in resistive memory is demonstrated using gold nanoparticles (GNPs). A GNP of 15 nm diameter is encapsulated by the porter protein and delivered to the designated positions. The restricted nanoscale filament formation by the GNP was observed by conductive atomic force microscopy, and writing and erasing were achieved in a defined area on the nanometer scale. The GNPs act as defect creators and assist the formation of nanoscale filaments with a low voltage.
Show PACS
84.30.Sk Pulse and digital circuits

Detecting ssDNA at single-nucleotide resolution by sub-2-nanometer pore in monoatomic graphene: A molecular dynamics study

Hu Qiu and Wanlin Guo

Appl. Phys. Lett. 100, 083106 (2012); http://dx.doi.org/10.1063/1.3686921 (4 pages) | Cited 1 time

Online Publication Date: 22 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Obtaining a sequence-based signal at a resolution of single nucleotide during the passage of a DNA strand through nanopores remains a challenging problem. Here, we demonstrate by molecular dynamics simulations that the single-base resolution detection can be realized by pulling a single-stranded DNA through graphene nanopores with diameters down to ∼1 nm. By simply monitoring and analyzing the peak values of the pulling force profile, each nucleotide in the DNA strand can be identified and characterized, except for cytosine and thymine which remain indistinguishable. This intriguing character through narrow nanopores should help realize the low-cost and time-efficient DNA sequencing.
Show PACS
87.15.ap Molecular dynamics simulation
02.60.-x Numerical approximation and analysis
Page 2 of 4 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close