Suharta, Wayan Gede (2013) Sintesis, Struktur Kristal Dan Sifat Magnetik Superkonduktor REBa2Cu3O7-0 (RE = Nd, Eu, Gd). Doctoral thesis, Institut Teknologi Sepuluh Nopember.
Preview |
Text
1107301202-Undergraduate_Thesis.pdf - Accepted Version Download (4MB) | Preview |
Preview |
Text
1107301202-Presentation.pdf - Presentation Download (2MB) | Preview |
Preview |
Text
1107301202-Paper.pdf - Accepted Version Download (583kB) | Preview |
Abstract
NdBa2Cu3O7-δ (Nd-123), NdxY1-xBa2Cu3O7-δ (NdxY1-x-123) and REBa2Cu3O7-δ
(RE-123) superconductors have been successfully synthesized by means of wet-mixing
method and HNO3 as digest agent. Nd-123 samples were calcined at 600oC for 3 hours,
cooled and re-grounded. Characterization results of X-ray diffraction (XRD) for Nd-
123 samples (600oC) show impurity phase of Ba(NO3)2, BaCO3, Nd2O3, CuO,
Nd2CuO4, Nd2BaO4, (Nd0,925Ba0,075)2CuO4-x, and Nd1,5Ba1,5Cu3O7,03, while the Nd-123
phase itself has not been detected at all. The addition of re-calcination temperatures
(650-970oC) was applied to eliminate impurities and to grow the Nd-123 phase, in
order to obtain an increase in the weight fraction of Nd-123 (84.3 to 95.9 %) phase.
Based on these results, NdxY1-x-123 and RE-123 samples were calcined at 600oC for 3
hours, cooled and re-grounded, then followed by re-calcination temperature at 970oC
for ten hours. Weight fractions obtained in NdxY1-x-123 samples were 96.6 to 97.0 %,
while they were approximately 96.9 to 98.8 % in the RE-123 samples. Characterization
of high-resolution neutron powder diffraction (HRPD) and synchrotron-ray diffraction
(SRD) were conducted for the Rietveld analysis with Rietica and FullProf programs.
Rietveld analysis results for NdxY1-x-123 samples showed that the addition of Nd
element (x = 0-1) resulting in increased values of lattice parameters, unit cell volume
and orthorhombisity, with the order from the smallest to the largest, namely Y-123,
Nd0,25Y0,75-123, Nd0,5Y0,5-123, Nd0,75Y0,25-123 and Nd-123. The addition of Nd
element on NdxY1-x-123 superconductors also resulted in the migration of oxygen as
shown by reduced oxygen occupancy factor at the position of O(4). Rietveld analysis
results of REBa2Cu3O7-δ, showed that the combination of RE resulted in changing the
values of the lattice parameters and the unit cell volume, with the order from the
smallest to the largest, ie Gd-123, Eu0,5Gd0,5-123, Eu-123,
Nd0,33Eu0,33Gd0,33Ba2Cu3O7-δ, Nd0,5Gd0,5-123, Nd0,5Eu0,5-123 and Nd-123.
Characterization using scanning electron microscopy (SEM) and transmission electron
microscopy (TEM) showed that the addition of re-calcination temperatures resulted in
larger particle sizes . Characterization results from superconducting quantum
interference device (SQUID) measurements showed that resistance of superconducting
property in a magnetic field of Nd0,5Y0,5Ba2Cu3O7-δ samples is greater than that of
Nd0,25Y0,75Ba2Cu3O7-δ samples. Characterization results from vibrating sample
magnetometer (VSM) for REBa2Cu3O7-δ samples with particle sizes smaller than 50 nm
exhibit ferromagnetic properties at room temperature, while the sample with particle
sizes larger than 100 nm shows paramagnetic properties. The addition of Nd element
vii
from x = 0,25 to become x = 0,5 in NdxY1-x-123 samples has increased the critical
temperature Tc (from 90,5 to 91,5 K) and the critical current density Jc (from 4 × 104
Acm-2 to 1 × 105 Acm-2). The critical temperature of REBa2Cu3O7-δ samples are in the
range of 88,5 and 93,6 K.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Additional Information: | RDFi 537.623 Suh s 3100014053479 |
| Uncontrolled Keywords: | Superconductor, wet-mixing method, re-calcination, ferromagnetic, XRD, SRD, HRPD, SQUID, critical temperature, critical current densitySuperconductor, wet-mixing method, re-calcination, ferromagnetic, XRD, SRD, HRPD, SQUID, critical temperature, critical current density |
| Subjects: | Q Science > QC Physics > QC611.97.C54 Superconductors |
| Divisions: | Faculty of Industrial Technology > Physics Engineering > 30001-(S3) PhD Thesis |
| Depositing User: | - Davi Wah |
| Date Deposited: | 16 Jan 2020 08:30 |
| Last Modified: | 16 Jan 2020 08:40 |
| URI: | http://repository.its.ac.id/id/eprint/72701 |
Actions (login required)
 |
View Item |