Yazar "Beyaz, Seda" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Polyethylene Glycol Modified ErVO4 Nanocrystals: Magnetic and Optical Properties
    (Amer Scientific Publishers, 2019) Bulbul, Berna; Beyaz, Seda; Akyol, Mustafa; Ekicibil, Ahmet
    Spindle-like ErVO4 nanocrystals were synthesized by precipitation in the presence of polyethylene glycol. Structural, optical and magnetic properties of as-prepared ErVO4 nanoparticles with and without polyethylene glycol were compared by X-ray diffraction, transmission electron microscopy, infrared spectroscopy, thermal gravimetric analysis, vibrating sample magnetometer, and ultraviolet-visible-near infrared spectroscopy. Crystal structures were tetragonal zircon type ErVO4 for both cases, and polyethylene glycol addition decreased average particle size from 70.69 to 38.78 nm, resulting more uniform particle formation. Polyethylene glycol proportion on ErVO4 surfaces was 9.8%, and its inclusion increased ErVO4 magnetization response to an external field as well as improving optical reflectivity, which is critical for nanophosphor use in biomedical fields.
  • [ X ]
    Öğe
    Simple manufacturing and metal type-dependent properties of M3 (OH)2 V2 O7·n H2 O (M; Co, Ni, Cu, Zn) nanostructures
    (Iranian Chemical Society, 2020) Bülbül, Berna; Beyaz, Seda; Akyol, Mustafa; Ekicibil, Ahmet
    M3 (OH)2 V2 O7·nH2 O (M: Co, Ni, Cu, Zn) nanostructures were synthesized by a simple and economic chemical precipitation route. For Co and Ni compounds, very small (~9 nm), irregularly shaped and poor crystalline nanoparticles occurred, probably due to high tendency for complexing with ammonia molecules releasing from ammonium metavanadate. However, more crystalline Co compounds could be synthesized in high reactant concentrations, but not for Ni. Zn and Cu compounds are well crystallized in the hexagonal and monoclinic unit cell, respectively. Their shapes were nanoflake or nanoplate and their thickness were about 20 nm and 25 nm, respectively. Both have an average diameter of less than 500 nm. The chemical formulas determined were Co3 V2 O7 (OH)2·2.8H2 O, Ni3 V2 O7 (OH)2·5.6H2 O, Cu3 V2 O7 (OH)2·2H2 O and Zn3 V2 O7 (OH)2·2.8H2 O. The band gaps of samples were found in the range from 3.22 to 4.34 eV. Magnetic measurements show that all Co samples have a magnetic transition from ferromagnetic (FM) to paramagnetic (PM) around 300 K, on the ground that samples with FM characteristics and coupling at 5 K temperature turn into PM samples at room temperature. These results are important for large-scale synthesis of nanovanadate structures. © 2020, Iranian Chemical Society. All rights reserved.