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31 Jan 2000

Volume 76, Issue 5, pp. 523-656

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Observation of an antiparallel magnetic state in Fe3O4/Mn3O4 superlattices

G. Chern, Lance Horng, T. Y. Hou, and M. Z. Lin

Appl. Phys. Lett. 76, 598 (2000); http://dx.doi.org/10.1063/1.125829 (3 pages) | Cited 7 times

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[Fe3O4(20 Å)/Mn3O4(80 Å)]x20 and [Fe3O4(20 Å)/MgO(80 Å)]x20 superlattices on MgO(001) are fabricated by molecular beam epitaxy in order to compare the magnetic coupling in ferrimagnetic–ferrimagnetic and ferrimagnetic–nonmagnetic systems. The magnetic response is measured as a function of applied-field (−50 to 50 kOe) parallel to the film surface and temperature (5–300 K). A strong reduction of magnetization, from 115 to 45 emu/cm3, is observed only from the Fe3O4/Mn3O4 superlattice at temperature below ∼60 K. This observation indicates that the magnetic moments in two constituents are antiparallel and the Curie temperature (Tc) of Mn3O4 is enhanced for 15 K. In addition, the remanent magnetization shows a compensation point (Tcp) at about 32 K at which the opposing spins are balanced. Detailed magnetic hysteresis loops measured at different temperature further explore magnetic phase transitions as a function of external field and temperature. A possible phase diagram is similar to the previous Gd/Fe multilayered system in that Mn3O4 is parallel and Fe3O4 antiparallel to the applied field below Tcp while Fe3O4 is parallel and Mn3O4 antiparallel to the applied field above Tcp. Moreover, a spin-flop-like phase is observed above a critical external field, H∗, ∼10 kOe. © 2000 American Institute of Physics.
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75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.50.Gg Ferrimagnetics
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.50.Ee Antiferromagnetics
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.25.-j Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.)

Fabrication of a Josephson junction using an atomic force microscope

Insang Song, Byong Man Kim, and Gwangseo Park

Appl. Phys. Lett. 76, 601 (2000); http://dx.doi.org/10.1063/1.125830 (3 pages) | Cited 15 times

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A Josephson junction was fabricated by inducing a selective surface modification on a YBa2Cu3O7−y strip with an atomic force microscope (AFM). The surface modification in the field of conductive AFM tip results in the controlled growth of protrusions across the entire strip. By properly regulating the extent of AFM modification, we achieved a Josephson junction. The self-radiation power of about 50 pW at a resonant frequency of 22 GHz was detected from this junction, which is in excellent agreement with the Josephson frequency-voltage relationship. © 2000 American Institute of Physics.
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85.25.Cp Josephson devices
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures
07.79.Lh Atomic force microscopes
74.72.-h Cuprate superconductors
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
74.25.N- Response to electromagnetic fields

Analyzing the polarization distribution in poled polymer films by scanning Kelvin microscopy

Robert Blum, Andrei Ivankov, Stefan Schwantes, and Manfred Eich

Appl. Phys. Lett. 76, 604 (2000); http://dx.doi.org/10.1063/1.125831 (3 pages) | Cited 2 times

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We present a method for analyzing the homogeneity of the χ(2) distribution in poled nonlinear optical polymer films. The second-order nonlinear coefficient in these polymers is commonly induced by electric-field poling methods which can lead to a χ(2) distribution with poor spatial homogeneity. In this letter, we analyze the χ(2) distribution using scanning Kelvin microscopy. This allows us to detect the height and the direction of the induced polarization through the probing of the countercharges that are present on the polymer surface. We compare the response to that obtained from the scanning second-harmonic microscopy method, in which the direction of the orientation, and thus the phase of χ(2), cannot be seen. © 2000 American Institute of Physics.
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42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.70.Jk Polymers and organics
77.22.Ej Polarization and depolarization
77.84.Jd Polymers; organic compounds
42.65.An Optical susceptibility, hyperpolarizability
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
73.25.+i Surface conductivity and carrier phenomena

Pinhole analysis in magnetic tunnel junctions

R. Schad, D. Allen, Giovanni Zangari, Iulica Zana, D. Yang, Mark Tondra, and Dexin Wang

Appl. Phys. Lett. 76, 607 (2000); http://dx.doi.org/10.1063/1.125832 (3 pages) | Cited 16 times

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Pinholes in the insulating layer of magnetic tunnel junctions are local shortcuts and cause malfunction of such devices. The need for reduction of the tunnel resistance by reduction of the insulator thickness will make this problem even more severe. Therefore, the development of low-resistance magnetic tunnel junctions requires analyzing the pinhole density. We developed a method for pinhole imaging using electrodeposition of copper. Selective nucleation at pinholes produces characteristic structures that can be visualized by conventional microscopy techniques. The experimental conditions were carefully chosen in order to avoid uncontrolled damage of the insulator layer. © 2000 American Institute of Physics.
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75.45.+j Macroscopic quantum phenomena in magnetic systems
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
68.35.Dv Composition, segregation; defects and impurities
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
81.15.Pq Electrodeposition, electroplating
75.50.Bb Fe and its alloys

Spin-tunnel-junction thermal stability and interface interdiffusion above 300 °C

S. Cardoso, P. P. Freitas, C. de Jesus, P. Wei, and J. C. Soares

Appl. Phys. Lett. 76, 610 (2000); http://dx.doi.org/10.1063/1.125833 (3 pages) | Cited 80 times

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Spin tunnel junctions (CoFe/Al2O3/CoFe/MnIr) were fabricated with tunneling magnetoresistance (TMR) of 39%–41% after anneal at 300 °C, decreasing to 4%–6% after anneal at 410 °C. Junction resistance decreases from (0.8–1.6) to (0.5–0.8) M Ω μm2 during anneal. The pinned-layer moment decreases by 44% after anneal at 435 °C, but the free-layer moment does not change. The current–voltage characteristics change significantly and become asymmetric above 300 °C. Rutherford backscattering analysis (RBS) shows that above 300 °C, strong interdiffusion starts at the CoFe/MnIr interface with Mn moving into CoFe, causing the electrode moment to decrease. Mn eventually reaches the Al2O3/CoFe interface contributing to the TMR decrease. RBS analysis of a separate CoFe/Al2O3/CoFe structure shows only minor structural changes at the CoFe/Al2O3 interfaces after anneal at 435 °C, possibly leading to a second mechanism for the loss of interface polarization and TMR. © 2000 American Institute of Physics.
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75.47.De Giant magnetoresistance
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
68.60.Dv Thermal stability; thermal effects
66.30.Ny Chemical interdiffusion; diffusion barriers
68.35.Fx Diffusion; interface formation
75.45.+j Macroscopic quantum phenomena in magnetic systems
82.80.Yc Rutherford backscattering (RBS), and other methods of chemical analysis

Control of domain structures and magnetotransport properties in patterned ferromagnetic wires

T. Taniyama, I. Nakatani, T. Yakabe, and Y. Yamazaki

Appl. Phys. Lett. 76, 613 (2000); http://dx.doi.org/10.1063/1.125834 (3 pages) | Cited 17 times

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Observations of controlled domain structures in zigzag patterned cobalt wires are demonstrated. Distinct domain structures are accessible by changing the orientation of magnetic field using the zigzag geometry, which provides a prospective potential to design the desired magnetic structures. Utilizing the subtle technique, we further throw light on the issue of magnetoresistance induced by the different domain structures. It is found that a negative contribution to the resistance is due to the spin configuration around the corner of the zigzag wires and shows an anomalous maximum around 100 K. © 2000 American Institute of Physics.
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75.50.Cc Other ferromagnetic metals and alloys
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
75.25.-j Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.)
75.60.Ch Domain walls and domain structure

Nanoscale magnetostrictive response in a thin film owing to a local magnetic field

R. Berger, F. Krause, A. Dietzel, J. W. Seo, J. Fompeyrine, and J.-P. Locquet

Appl. Phys. Lett. 76, 616 (2000); http://dx.doi.org/10.1063/1.125835 (3 pages) | Cited 1 time

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Scanning probe microscope experiments are presented in which thin magnetostrictive films deposited on top of micrometer-sized magnetic write heads as used in magnetic hard disk drives, are used to visualize their emanating magnetic field. The magnetostrictive expansion owing to magnetic writing fields is discussed, together with the transduction mechanisms that lead to the vertical and lateral contrast observed. Experimental results verify that the techniques described have a lateral resolution in the realm of 100 nm. © 2000 American Institute of Physics.
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75.70.Ak Magnetic properties of monolayers and thin films
75.50.Kj Amorphous and quasicrystalline magnetic materials
75.80.+q Magnetomechanical effects, magnetostriction

Microscopic magnetization reversal in perpendicular anisotropy CoCr thin films

Gottfried Wastlbauer, George D. Skidmore, Chris Merton, Jake Schmidt, E. Dan Dahlberg, and Joseph Skorjanec

Appl. Phys. Lett. 76, 619 (2000); http://dx.doi.org/10.1063/1.125837 (3 pages) | Cited 6 times

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Magnetic force microscopy was used to observe the magnetization reversal in a CoCr thin film on a grain/subgrain scale. The combination of high resolution topographic and magnetic images were used to relate microscopic magnetization changes to the microstructure of the sample. Both uniformly and partially magnetized grains and both uniform and partial magnetization reversal were observed. Statistically, the uniform magnetic state was more prevalent. In addition, there was a visualization of the flux closure between grains. © 2000 American Institute of Physics.
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75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.50.Cc Other ferromagnetic metals and alloys
75.70.Ak Magnetic properties of monolayers and thin films
61.72.-y Defects and impurities in crystals; microstructure
68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)

Two-dimensional magnetic switching of micron-size films in magnetic tunnel junctions

A. Anguelouch, B. D. Schrag, Gang Xiao, Yu Lu, P. L. Trouilloud, R. A. Wanner, W. J. Gallagher, and S. S. P. Parkin

Appl. Phys. Lett. 76, 622 (2000); http://dx.doi.org/10.1063/1.125838 (3 pages) | Cited 27 times

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The magnetic switching behavior of micron-size magnetic tunnel junctions has been studied in two-dimensional magnetic fields. By measuring junction resistance, we obtain information about the magnetization state of the free ferromagnetic layer. Magnetic properties of this layer are explored using the Stoner–Wohlfarth rotational model as a starting point. We use geometric parameters of the critical curves to obtain information about interlayer coupling and domain structure effects in the free layer. © 2000 American Institute of Physics.
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75.47.De Giant magnetoresistance
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.45.+j Macroscopic quantum phenomena in magnetic systems
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
75.70.Kw Domain structure (including magnetic bubbles and vortices)
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Composition-control of magnetron-sputter-deposited (BaxSr1−x)Ti1+yO3+z thin films for voltage tunable devices

Jaemo Im, O. Auciello, P. K. Baumann, S. K. Streiffer, D. Y. Kaufman, and A. R. Krauss

Appl. Phys. Lett. 76, 625 (2000); http://dx.doi.org/10.1063/1.125839 (3 pages) | Cited 158 times

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Precise control of composition and microstructure is critical for the production of (BaxSr1−x)Ti1+yO3+z (BST) dielectric thin films with the large dependence of permittivity on electric field, low losses, and high electrical breakdown fields that are required for successful integration of BST into tunable high-frequency devices. Here, we present results on composition-microstructure-electrical property relationships for polycrystalline BST films produced by magnetron-sputter deposition, that are appropriate for microwave and millimeter-wave applications such as varactors and frequency triplers. Films with controlled compositions were grown from a stoichiometric Ba0.5Sr0.5TiO3 target by control of the background processing gas pressure. It was determined that the (Ba+Sr)/Ti ratios of these BST films could be adjusted from 0.73 to 0.98 by changing the total (Ar+O2) process pressure, while the O2/Ar ratio did not strongly affect the metal ion composition. Film crystalline structure and dielectric properties as a function of the (Ba+Sr)/Ti ratio are discussed. Optimized BST films yielded capacitors with low dielectric losses (0.0047), among the best reported for sputtered BST, while still maintaining tunabilities suitable for device applications. © 2000 American Institute of Physics.
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77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
84.32.Tt Capacitors
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
81.15.Cd Deposition by sputtering
68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
77.22.Ch Permittivity (dielectric function)
77.22.Gm Dielectric loss and relaxation
77.22.Jp Dielectric breakdown and space-charge effects
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Analysis of submicron carbon nanotube field-effect transistors

Toshishige Yamada

Appl. Phys. Lett. 76, 628 (2000); http://dx.doi.org/10.1063/1.125840 (3 pages) | Cited 9 times

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A theoretical analysis of carbon nanotube based field-effect transistors fabricated by two different groups [Tans et al., Nature (London) 393, 49 (1998); Martel et al., Appl. Phys. Lett. 73, 2447 (1998)] is presented. The metal (electrode)-semiconductor (nanotube) contact influences subthreshold channel conductance versus gate voltage VG, such that the occurrence of a kink depends on the transport mechanism across this contact. Saturation in the turn-on drain current ID vs VG seen in experiments reflects the nanotube state density. Saturationless ID versus drain voltage VD indicates transport in the weak-localization regime in the absence of carrier–carrier scattering so that pinch-off cannot occur. To compensate for saturationless ID(VD) in digital applications, nanotube transistors need to be designed to maximize their transconductance. © 2000 American Institute of Physics.
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85.30.Tv Field effect devices
85.65.+h Molecular electronic devices
85.30.De Semiconductor-device characterization, design, and modeling
73.20.Fz Weak or Anderson localization

GaN microdisk light emitting diodes

S. X. Jin, J. Li, J. Z. Li, J. Y. Lin, and H. X. Jiang

Appl. Phys. Lett. 76, 631 (2000); http://dx.doi.org/10.1063/1.125841 (3 pages) | Cited 40 times

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Microdisk light-emitting diodes (μ-LEDs) with diameter of about 12 μm have been fabricated from InGaN/GaN quantum wells. Photolithographic patterning and inductively coupled plasma dry etching have been employed to fabricate these μ-LED devices. Device characteristics, such as the current–voltage characteristics, light output power, and electroluminescence (EL) spectra have been measured and compared with those of conventional broad-area LEDs. Our results showed that, for an identical area, the quantum efficiencies of μ-LED are enhanced over the conventional broad-area LEDs due to an enhanced current density and possibly microsize effects. The implications of our results on the design of future UV/blue microoptoelectronic devices are discussed. © 2000 American Institute of Physics.
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85.60.Jb Light-emitting devices
81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition

High luminescent efficiency in light-emitting polymers due to effective exciton confinement

R. G. Sun, Y. Z. Wang, D. K. Wang, Q. B. Zheng, E. M. Kyllo, T. L. Gustafson, and A. J. Epstein

Appl. Phys. Lett. 76, 634 (2000); http://dx.doi.org/10.1063/1.125842 (3 pages) | Cited 14 times

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Highly efficient light-emitting polymers have become possible by molecular engineering. Photoluminescence (PL) quantum yield above 90% in the solid state is reported for the alternating block copolymer of distyrylbenzene. We conclude that the alternate arrangement of conjugated and nonconjugated segments with surrounding side groups for chromophores effectively confine the excitons for radiative emission. The effectiveness of the exciton confinement is confirmed through the temperature independence of the PL quantum yield. The time-resolved PL decay measurement supports this model through the independence of the PL yield on temperature and emission wavelength. The synthesized copolymers have been employed for the fabrication of electroluminescent (EL) devices, demonstrating high external EL efficiency with low operation threshold. © 2000 American Institute of Physics.
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78.55.Kz Solid organic materials
71.35.-y Excitons and related phenomena
78.47.-p Spectroscopy of solid state dynamics
85.60.Jb Light-emitting devices

Multigate single-electron transistors and their application to an exclusive-OR gate

Yasuo Takahashi, Akira Fujiwara, Kenji Yamazaki, Hideo Namatsu, Kenji Kurihara, and Katsumi Murase

Appl. Phys. Lett. 76, 637 (2000); http://dx.doi.org/10.1063/1.125843 (3 pages) | Cited 35 times

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The two-input exclusive-OR (XOR) function was implemented by a multigate single-electron transistor (SET). Two types of multigate SETs operating at 40 K were fabricated on a top silicon layer of an Si-on-insulator wafer by using a special technique called pattern-dependent oxidation. Two small gate electrodes which act as the input gates were formed over the small SET island. The output current of the devices took a high level when a high voltage was applied to either of the two gates with the other gate grounded, while it took a low level when both gates were grounded or fed with a high voltage. It is striking that such an XOR function can be implemented with just one device. © 2000 American Institute of Physics.
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85.35.Gv Single electron devices
84.30.Sk Pulse and digital circuits
81.65.Mq Oxidation

Nonlinearity and electrothermal feedback of high Tc transition edge bolometers

H. Neff, A. M. N. Lima, G. S. Deep, R. C. S. Freire, E. Melcher, I. A. Khrebtov, and A. D. Tkachenko

Appl. Phys. Lett. 76, 640 (2000); http://dx.doi.org/10.1063/1.125844 (3 pages) | Cited 4 times

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The effects of electrothermal feedback on the performance of a micromachined superconducting high Tc transition edge bolometer, over a temperature range 85–95 K, have been investigated. The system behaves nonlinearly, due to the variation of the resistance-temperature coefficient β with temperature. Optimum operating points of constant current mode (CCM) and constant voltage mode (CVM) modes vary with temperature and biasing conditions. In CCM, effective response time τeff varies little with temperature. The optimum output signal of CVM occurs at approximately 3–5 K lower temperature within the tail region, where β is maximum. The biasing voltage also displays a maximum, above which the bolometric performance degrades. The CCM exhibits a comparatively limited linear dynamic range. Negative thermal feedback causes a decrease of τeff of up to 2 orders of magnitude in CVM. CCM requires precise thermal stabilization at midtransition. Noise in both modes is limited by the 1/f contribution. Maximum D∗ values are slightly higher for CVM at higher frequencies. Bolometer operation in the CVM mode requires cooling the heatsink below 77 K, but does not need accurate temperature control. © 2000 American Institute of Physics.
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07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors
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Scanning tunneling microscopy on the formation of lipoamide-cyclodextrin monolayer on Au(111)

Satoshi Yasuda, Hidemi Shigekawa, Iwao Suzuki, Tohru Nakamura, Mutsuyoshi Matsumoto, and Makoto Komiyama

Appl. Phys. Lett. 76, 643 (2000); http://dx.doi.org/10.1063/1.125845 (3 pages) | Cited 6 times

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β-cyclodextrin molecules modified with lipoamide residue (LP-β-CyD) were self-assembled on an Au(111) surface in ethanol solution, and the growth process was studied by scanning tunneling microscopy. At the initial stage, adsorption sites were not only random, but also partially linear ordering, which suggests the existence of some influence by the herringbone structure of the Au(111) surface. According to the macroscopic analysis, the subsequent growth process was explained by the Elovich model, which is based on the repulsive interaction between adsorbed molecules. However, when the immersion time increased, island structures began forming. This result suggests the interaction between LP-β-CyD molecules as attractive, which in fact is more probable in consideration of the possibility of the hydrophobic and the hydrogen bonding interactions between CyD molecules. Finally, formation of a single LP-β-CyD layer was clearly confirmed. © 2000 American Institute of Physics.
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68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.18.-g Langmuir-Blodgett films on liquids
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.-a Thin film structure and morphology
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Implementation of a three-quantum-bit search algorithm

Lieven M. K. Vandersypen, Matthias Steffen, Mark H. Sherwood, Costantino S. Yannoni, Gregory Breyta, and Isaac L. Chuang

Appl. Phys. Lett. 76, 646 (2000); http://dx.doi.org/10.1063/1.125846 (3 pages) | Cited 52 times

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We report the experimental implementation of Grover’s quantum search algorithm on a quantum computer with three quantum bits. The computer consists of molecules of 13C-labeled CHFBr2, in which the three weakly coupled spin-1/2 nuclei behave as the bits and are initialized, manipulated, and read out using magnetic resonance techniques. This quantum computation is made possible by the introduction of two techniques which significantly reduce the complexity of the experiment and by the surprising degree of cancellation of systematic errors which have previously limited the total possible number of quantum gates. © 2000 American Institute of Physics.
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03.67.Lx Quantum computation architectures and implementations
85.65.+h Molecular electronic devices
33.25.+k Nuclear resonance and relaxation

Delayed release of Li atoms from laser ablated lithium niobate

J. A. Chaos, R. W. Dreyfus, A. Perea, R. Serna, J. Gonzalo, and C. N. Afonso

Appl. Phys. Lett. 76, 649 (2000); http://dx.doi.org/10.1063/1.125847 (3 pages) | Cited 10 times

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The present vapor-phase optical (atomic) absorption measurements study the escape dynamics of Li atoms from a LiNbO3 target surface upon laser ablation in vacuum. The objective is to understand the low-Li content of LiNbO3 films prepared by pulsed laser deposition. A primary result is a delayed release of Li atoms, 2–20 μs after the laser pulse; they eject with a velocity of 6×105 cm s−1, which is consistent with an electronic ejection mechanism. The long emission period means there are almost no intraplume Li collisions in the gas phase and no forward focusing of the delayed released atoms. This appears to explain the low-Li content usually found in films grown in the normal direction. © 2000 American Institute of Physics.
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79.20.Ds Laser-beam impact phenomena
81.15.Fg Pulsed laser ablation deposition
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)

Synthesis of GaN–carbon composite nanotubes and GaN nanorods by arc discharge in nitrogen atmosphere

Weiqiang Han, Philipp Redlich, Frank Ernst, and Manfred Rühle

Appl. Phys. Lett. 76, 652 (2000); http://dx.doi.org/10.1063/1.125848 (3 pages) | Cited 90 times

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A method using an arc discharge in a nitrogen atmosphere for synthesizing large quantities of gallium nitride (GaN)–Carbon composite nanotubes and GaN nanorods is reported. The reaction is achieved by a dc arc discharge between a graphite anode filled with a mixture of GaN, graphite, and nickel powders and a graphite cathode in a nitrogen atmosphere. The GaN are presented as rodlike fillings in the composite tubes and the isolated GaN nanorods have diameters in the range of 7–45 nanometers and a length of up to 40 μm. The outer graphitic shells of the composite carbon nanotubes have thicknesses ranging from 1 to 8 nm. It was found that the use of a nitrogen atmosphere plays a crucial role for the growth of the GaN nanorods fillings and the individual GaN nanorods. © 2000 American Institute of Physics.
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81.07.-b Nanoscale materials and structures: fabrication and characterization
61.46.-w Structure of nanoscale materials
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
81.05.ub Fullerenes and related materials
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
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Comment on “Fermi-edge singularity observed in a modulation-doped AlGaN/GaN heterostructure” [Appl. Phys. Lett. 73, 2471 (1998)]

B. Monemar, J. P. Bergman, and P. O. Holtz

Appl. Phys. Lett. 76, 655 (2000); http://dx.doi.org/10.1063/1.125849 (1 page) | Cited 1 time

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© 2000 American Institute of Physics.
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78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
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Erratum: “Quantitative microwave evanescent microscopy” [Appl. Phys. Lett. 75, 3005 (1999)]

Chen Gao, Fred Duewer, and X.-D. Xiang

Appl. Phys. Lett. 76, 656 (2000); http://dx.doi.org/10.1063/1.125850 (1 page) | Cited 2 times

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84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment
07.79.-v Scanning probe microscopes and components
99.10.Cd Errata
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