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Nanodot Arrays (nanodot + array)

Distribution by Scientific Domains
Polymers and Materials Science60%

Selected Abstracts

High-Density Periodically Ordered Magnetic Cobalt Ferrite Nanodot Arrays by Template-Assisted Pulsed Laser Deposition

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Xingsen Gao
Abstract A novel nanopatterning method using pulsed laser deposition through an ultrathin anodic aluminium oxide (AAO) membrane mask is proposed to synthesize well-ordered nanodot arrays of magnetic CoFe2O4 that feature a wide range of applications like sensors, drug delivery, and data storage. This technique allows the adjustment of the array dimension from ,35 to ,300,nm in diameter and ,65 to ,500,nm in inter-dot distance. The dot density can be as high as 0.21 Terabit in.,2. The microstructure of the nanodots is characterized by SEM, TEM, and XRD and their magnetic properties are confirmed by well-defined magnetic force microscopy contrasts and by hysteresis loops recorded by a superconducting quantum interference device. Moreover, the high stability of the AAO mask enables the epitaxial growth of nanodots at a temperature as high as 550,°C. The epitaxial dots demonstrate unique complex magnetic domains such as bubble and stripe domains, which are switchable by external magnetic fields. This patterning method creates opportunities for studying novel physics in oxide nanomagnets and may find applications in spintronic devices. [source]

On dot and out of dot electrical characteristics of silicon oxide nanodots patterned by scanning probe lithography

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2009
Sabar D. Hutagalung
Abstract Silicon oxide nanodot arrays were grown on pre-cleaned silicon (100) substrate by scanning probe nanolithography. In this study, a conductive AFM was used to fabricate nanoscale oxide dots in humidity controlled environment. The AFM is equipped with a nanotechnology software package providing the control of tip-sample voltage and tip motion according to pre-designed patterns. The surface topography and size of obtained patterns (diameter and height) were investigated by a noncontact AFM mode. A series of five silicon oxide nanodot array with diameter in the range of 146.05-247.65 nm and height 2.14-4.87 nm had been successfully fabricated. Meanwhile, a contact AFM mode was used to investigate the localized I-V characteristics on the dots and out of dot position. It was found, the on dot characteristics are highly nonohmic due to potential barrier interface between silicon oxide and silicon substrate. However, the out of dot characteristic is linear indicates an ohmic contact between AFM tip and sample. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

High-Density Periodically Ordered Magnetic Cobalt Ferrite Nanodot Arrays by Template-Assisted Pulsed Laser Deposition

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Xingsen Gao
Abstract A novel nanopatterning method using pulsed laser deposition through an ultrathin anodic aluminium oxide (AAO) membrane mask is proposed to synthesize well-ordered nanodot arrays of magnetic CoFe2O4 that feature a wide range of applications like sensors, drug delivery, and data storage. This technique allows the adjustment of the array dimension from ,35 to ,300,nm in diameter and ,65 to ,500,nm in inter-dot distance. The dot density can be as high as 0.21 Terabit in.,2. The microstructure of the nanodots is characterized by SEM, TEM, and XRD and their magnetic properties are confirmed by well-defined magnetic force microscopy contrasts and by hysteresis loops recorded by a superconducting quantum interference device. Moreover, the high stability of the AAO mask enables the epitaxial growth of nanodots at a temperature as high as 550,°C. The epitaxial dots demonstrate unique complex magnetic domains such as bubble and stripe domains, which are switchable by external magnetic fields. This patterning method creates opportunities for studying novel physics in oxide nanomagnets and may find applications in spintronic devices. [source]

Growth and Optical Properties of Highly Uniform and Periodic InGaN Nanostructures,

ADVANCED MATERIALS, Issue 13 2007
P. Chen
InGaN nanodot arrays with improved optical properties, attributed to the strong localization of photogenerated carriers in the size-homogeneous nanodots, grown by nanoscale selective area epitaxy (NSAE) on electron-beam lithographically patterned templates are presented. The figure shows an array of 60,nm diameter cone-shaped InGaN nanodots with 200,nm spacing, and a single nanodot (inset). [source]

On dot and out of dot electrical characteristics of silicon oxide nanodots patterned by scanning probe lithography

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2009
Sabar D. Hutagalung
Abstract Silicon oxide nanodot arrays were grown on pre-cleaned silicon (100) substrate by scanning probe nanolithography. In this study, a conductive AFM was used to fabricate nanoscale oxide dots in humidity controlled environment. The AFM is equipped with a nanotechnology software package providing the control of tip-sample voltage and tip motion according to pre-designed patterns. The surface topography and size of obtained patterns (diameter and height) were investigated by a noncontact AFM mode. A series of five silicon oxide nanodot array with diameter in the range of 146.05-247.65 nm and height 2.14-4.87 nm had been successfully fabricated. Meanwhile, a contact AFM mode was used to investigate the localized I-V characteristics on the dots and out of dot position. It was found, the on dot characteristics are highly nonohmic due to potential barrier interface between silicon oxide and silicon substrate. However, the out of dot characteristic is linear indicates an ohmic contact between AFM tip and sample. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]