Person:
YUMUŞAK, GÖRKEM

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

YUMUŞAK

First Name

GÖRKEM

Name

Filters

2017 - 20182
Reset filters

Settings

End date: 2018 ×

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    PublicationMetadata only
    Gd and Tb doping effects on the physical properties of Nd2Sn2O7
    (ELSEVIER SCI LTD, 2018) YUMUŞAK, GÖRKEM; Saleh, Adli A.; Hamamera, Hanan Z.; Khanfar, Hazem K.; Qasrawi, A. F.; Yumusak, G.
    In the current study, we report the light doping effects of the gadolinium and the terbium on the structural, morphological, optical and electrical properties of Nd2Sn2O7 pyrochlore ceramics. The pyrochlore which is prepared by the conventional solid state reaction technique is analyzed by means of scanning electron microscopy, energy dispersive X-ray analyzer, X-ray diffraction, ultraviolet- visible light spectrophotometry and temperature dependent current -voltage characteristics techniques. It is found that even though the doping content of both metals is low (2%), they significantly alter the physical properties of the pyrochlore. Particularly, it is observed that, these two doping agents increases the lattice parameter and strain and reduces the crystallite size and dislocation density. Optically, the effect of Gd doping on shrinking the energy band gap value of the Nd(2)Sn(2)O(7 )pyrochlore ceramic is more pronounced than that of Tb. On the other hand, the electrical investigations have shown that while the Gd make the pyrochlore exhibit p-type conductivity through forming shallow acceptor levels, the Tb forces n-type conductivity by forming deep donor levels below the conduction band edge. Such acceptor and donor impurity levels increases the electrical conductivity of the Nd(2)Sn(2)O(7 )pyrochlore ceramics by 390 and 58 times, respectively.
  • Thumbnail Image
    PublicationOpen Access
    Physical properties of neodymium tin oxide pyrochlore ceramics
    (DE GRUYTER POLAND SP ZOO, 2017-10-20) YUMUŞAK, GÖRKEM; Saleh, Adli A.; Qasrawi, A. F.; Yumusak, G.; Mergen, A.
    In this work, physical properties of neodymium tin oxide pyrochlore ceramics prepared by solid state reaction technique are investigated by means of X-ray diffraction, scanning electron microscopy, ultraviolet-visible light (UV-Vis) spectrophotometry and temperature dependent electrical resistivity measurements. The pyrochlore is observed to have a cubic FCC crystal lattice with lattice parameter of 10.578 angstrom. The planes of the cubic cell are best oriented in the [2 2 2] direction. From the X-ray, the UV-Vis spectrophotometry and the electrical resistivity data analysis, the grain size, strain, dislocation density, optical and thermal energy band gaps, localized energy band tail states and resistivity activation energies are determined and discussed. The pyrochlore is observed to have an optical energy band gap of similar to 3.40 eV. This value corresponds to 365 nm UV light spectra which nominates the neodymium tin oxide pyrochlore ceramics for the use as UV sensors.