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Friday, April 30, 2010

Synthesis of colour tunable lanthanide-ion doped NaYF4 upconversion nanoparticles by controlling temperature

Synthesis of colour tunable lanthanide-ion doped NaYF4 upconversion nanoparticles by controlling temperature: "


Wenbin Niu, Suli Wu, Shufen Zhang, Lian Li

(Communication from Chem. Commun.)

Wenbin Niu, Chem. Commun., 2010, DOI: 10.1039/c002615h

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High magnetization aqueous ferrofluid: A simple one-pot synthesis

High magnetization aqueous ferrofluid: A simple one-pot synthesis: "Kyler J. Carroll, Michael D. Shultz, Panos P. Fatouros, and Everett E. Carpenter
A one-step polyol method was utilized to prepare a stable aqueous iron/iron oxide ferrofluid. The dried powders were characterized by x-ray diffraction, electron microscopy, x-ray absorption spectroscopy, and vibrating sample magnetometry for the determination of phase, morphology, and magnetic prop ... [J. Appl. Phys. 107, 09B304 (2010)] published Tue Apr 20, 2010."

Monday, April 19, 2010

CdSe Quantum Rod Formation Aided By In Situ TOPO Oxidation

CdSe Quantum Rod Formation Aided By In Situ TOPO Oxidation: "Chemistry of Materials, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Green luminescent ZnO:Cu2+ nanoparticles for their applications in white-light generation from UV LEDs

Green luminescent ZnO:Cu2+ nanoparticles for their applications in white-light generation from UV LEDs: "

Abstract  
Copper doped ZnO nanoparticles were synthesized by a chemical technique based on a hydrothermal method. The crystallite sizes,
estimated by XRD and TEM/SEM for different doping percentage of Cu2+ (1–10%), were found to be in the range of ~10–15 nm. TEM/SEM images showed formation of uniform nanorods, the aspect ratio
of which varied with doping percentage. Photoluminescence (PL) measurement showed strong green visible emission and PL intensity
was found enhanced with increase in doping percentage. The increase in the PL intensity was mainly due to Cu incorporation
in ZnO lattice. Currently, light-emitting diodes (LEDs) giving ultraviolet emission have been combined with broad-band visible
green phosphors to make white-light LEDs. Thus, green luminescent ZnO:Cu2+ nanoparticles are seen as necessary and condemnatory constituent for white-light generation from UV LEDs, underlying the
importance of the current work.

  • Content Type Journal Article
  • Category Research Paper
  • DOI 10.1007/s11051-010-9916-3
  • Authors
    • Prashant K. Sharma, University of Allahabad Nanotechnology Application Centre (Formerly Nanophosphor Application Centre) Allahabad 211002 India
    • Manvendra Kumar, University of Allahabad Nanotechnology Application Centre (Formerly Nanophosphor Application Centre) Allahabad 211002 India
    • Avinash C. Pandey, University of Allahabad Nanotechnology Application Centre (Formerly Nanophosphor Application Centre) Allahabad 211002 India
"

Stable colloidal suspensions of nanostructured zirconium oxide synthesized by hydrothermal process

Stable colloidal suspensions of nanostructured zirconium oxide synthesized by hydrothermal process: "

Abstract  
Nanocrystalline zirconium oxide was synthesized by hydrothermal treatment of ZrO(NO3)2 and ZrOCl2 aqueous solutions at different temperatures and time in presence of hydrogen peroxide. Hydrothermal treatment of zirconium
salts (0.25 and 0.50 mol L−1) produced nanocrystalline monoclinic ZrO2 powders with narrow size distribution, which were formed by the attachment of the smaller particles with crystallites size
of 3.5 nm, estimated by means of the Scherrer’s equation and confirmed by transmission electronic microscopy. Typical monoclinic
zirconium oxide X-ray powder diffraction patterns and Raman spectra were obtained for all the crystalline powders. It was
observed that the crystallization depends strongly on the temperature, resulting in amorphous material when the synthesis
was realized at 100 °C, and crystalline with monoclinic phase when synthesized at 110 °C, independently of the salt used.
Zirconium oxide colloidal nanoparticles were formed only at hydrothermal treatments longer than 24 h. The stability of the
colloids was successfully characterized of zeta potential, showing an initial value of + 59.2 mV in acid media and isoelectric
point at pH = 5.2, in good agreement with previous studies.

  • Content Type Journal Article
  • Category Research Paper
  • DOI 10.1007/s11051-010-9906-5
  • Authors
    • Tatiane M. Arantes, LIEC Department of Chemistry UFSCar. Rod.Washington Luis km 235 São Carlos SP 13565 Brazil
    • Giovanni P. Mambrini, LIEC Department of Chemistry UFSCar. Rod.Washington Luis km 235 São Carlos SP 13565 Brazil
    • Daniel G. Stroppa, LME Brazilian Synchrotron Light Laboratory Campinas SP Brazil
    • Edson R. Leite, LIEC Department of Chemistry UFSCar. Rod.Washington Luis km 235 São Carlos SP 13565 Brazil
    • Elson Longo, UNESP Institute of Chemistry Araraquara SP Brazil
    • Antonio J. Ramirez, LME Brazilian Synchrotron Light Laboratory Campinas SP Brazil
    • Emerson R. Camargo, LIEC Department of Chemistry UFSCar. Rod.Washington Luis km 235 São Carlos SP 13565 Brazil
"

Ferromagnetism in Cu-doped ZnSe semiconducting quantum dots

Ferromagnetism in Cu-doped ZnSe semiconducting quantum dots: "

Abstract  
The projection of integrating optical, magnetic and electronic functionalities into a single material have aggravated passionate
attention in mounting wide band gap diluted magnetic semiconductor (DMS) in the midst of room temperature ferromagnetism.
We report the evidence of ferromagnetism in Cu-doped ZnSe quantum dots (QDs) below room temperature, grown from a single source
precursor by lyothermal method with the sizes of approximately 3.2–5.14 nm. QDs mainly exhibit paramagnetic behavior between
80 and 300 K, with a weak ferromagnetic/anti-ferromagnetic exchange at lower temperature as observed by superconducting quantum
interference device (SQUID) magnetometer. From the Curie–Weiss behavior of the susceptibility, Curie temperature (T
c) of Cu-doped ZnSe sample has been evaluated. From EPR, we obtain the Lande-g factor in the Zeeman interaction term as 2.060. Photoluminescence and EPR measurements support and confirm the view that
Cu2+ substitutes for Zn2+ in Cu-doped ZnSe quantum dots.

  • Content Type Journal Article
  • Category Research Paper
  • DOI 10.1007/s11051-010-9914-5
  • Authors
    • Pushpendra Kumar, Banaras Hindu University Department of Physics, Faculty of Science Varanasi 221005 India
    • Kedar Singh, Banaras Hindu University Department of Physics, Faculty of Science Varanasi 221005 India
"

Thursday, April 08, 2010

High quality self-assembly magnetite (Fe3O4) chain-like core-shell nanowires with luminescence synthesized by a facile one-pot hydrothermal process

High quality self-assembly magnetite (Fe3O4) chain-like core-shell nanowires with luminescence synthesized by a facile one-pot hydrothermal process: "


Junyan Gong, Shanzhong Li, Dongen Zhang, Xiaobo Zhang, Chao Liu, Zhiwei Tong

(Communication from Chem. Commun.)

Junyan Gong, Chem. Commun., 2010, DOI: 10.1039/c002199g

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The content of this RSS Feed (c) The Royal Society of Chemistry"

From Ag Nanoprisms to Triangular AuAg Nanoboxes

From Ag Nanoprisms to Triangular AuAg Nanoboxes: "


Galvanic replacement reactions are successfully employed to produce enclosed triangular AuAg nanoboxes from a Ag nanoprism template (left). The interior cavity is clearly revealed by TEM images of edge-oriented nanoparticles (right). These are exciting candidates for the encapsulation and transport of drugs and other interesting materials.

[Full Paper]
Damian Aherne, Matthew Gara, John M. Kelly, Yurii K. Gun'ko
Adv. Funct. Mater., March 30, 2010, DOI: 10.1002/adfm.200902030. Read article.

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