J Supercond Nov Magn (2017) 30:2451–2456
Investigation and Comparing the Effects of CNTs and Ag
Nanoparticles Doping on YBCO Superconductor Properties
· Masoumeh Davoudiniya
· Sousan Dehghani
Received: 7 February 2017 / Accepted: 16 March 2017 / Published online: 7 April 2017
© Springer Science+Business Media New York 2017
Abstract In this work, we investigate and compare dop-
ing effects of Ag nanoparticles and carbon nanotubes
(CNTs) on the properties of Y
temperature superconductor. The YBCO samples were pre-
pared using sol-gel method and characterized by resistivity
versus temperature (ρ–T), the electrical field versus current
density (E–J), x-ray diffraction (XRD) and scanning elec-
tron microscope (SEM) analysis. The results show that the
orthorhombic phase of superconductivity was formed for all
the prepared samples. Also, we found that the crystalline
size of the YBCO samples decreases from 62 to 33 nm
by adding CNTs and Ag nanoparticles to the compound.
The pinning energy, critical current density and critical tem-
perature of the samples increase by adding CNTs and Ag
nanoparticles to YBCO compound, but CNTs play a more
effective role than Ag nanoparticles in this compound.
Keywords High-temperature superconductor · YBCO ·
Ag nanoparticles · Carbon nanotubes · Critical current
Nanotechnology is the study and controlling matter at
the nanoscale. This unique phenomena has many applica-
tions in their special physical and chemical properties .
Department of Physics, Alzahra University, Tehran,
The novel properties of nanoparticles have been used
in numerous products and industrial applications [2–4].
Among the nanoparticles, Ag nanoparticles have attracted
more interest due to their applicable chemical, physica and
biological properties compared to their larger counterparts
Carbon nanotubes (CNTs) were discovered by Iijima
(1991). CNTs have many applications due to their unique
mechanical strength and electrical and thermal conductiv-
ity properties . In the recent years, the applications of
CNTs in the form of composite materials like polymer and
superconductors have received great attention. Also, dop-
ing nanoparticles and carbon nanotubes to high-temperature
superconductors (HTSCs) create additional flux pinning
energy and thus increases the critical current density [7, 8].
(YBCO) high-temperature super-
conductor is the first superconductor discovered to have a
above the nitrogen boiling temperature (about 92 K).
These HTSCs have low critical current density (J
The critical current density J
enhances by effective meth-
ods containing some doping materials like nanoparticles
and carbon nanostructures which can act as effective pin-
ning centres. Also, they cause reinforcement in the weak
links and improvement of connections between the grains
[10–13]. There are many reports that doping YBCO high-
temperature superconductor by CNTs or Ag nanoparticles
significantly increase the critical current density [7, 14].
The goal of this research was to synthesize and character-
ize the YBCO (bulk) doped with different weight percent-
age of CNTs and Ag nanoparticles and compare the effects
of Ag nanoparticles and CNT doping on the properties of
these superconductor compounds. Therefore, the novelty of
this work is finding the competition effects between these
two nanostructures doping in YBCO compounds.