The polycrystalline samples of YBa2Cu3O7-x High-Temperature Superconductor (HTS), also called „YBCO-123”, were prepared by mixing (II) oxide (CuO), carbonate (BaCO3) and yttrium (III) oxide (Y2O3) powders and followed by a heat treatment high temperature (900 °C - 950 °C) flowing oxygen. The polycrystalline samples of YBCO-Fe composites were prepared by grinding the mixture of single phased YBCO-123 and small of iron (1% and 3% wt.), followed over by a heat treatment . The results of structural (SEM, EDS, Raman spectroscopy), magnetic (AC susceptibility and magnetization measurements) and magneto-transport on produced composites will be presented. Scanning electron microscopy (SEM) for YBCO and Fe mixtures showed iron particles homogeneously placed on YBCO grains boundaries. As the concentration of iron particles increased the critical temperature decreased. The magnetization measurements LN temperature revealed transition from diamagnetic to paramagnetic behaviour of YBCO-Fe samples originated from the iron grains.

1. Preparation and properties of polycrystalline YBa2Cu3O7-x and Fe mixtures
Paweł Pęczkowski1*
, Marcin Kowalik2
, Krzysztof Pomorski3
, Waldemar Tokarz2
, Wiesław Marek Woch2
, Cezariusz Jastrzębski4
The 2018 European Materials Reserach Society Fall Meeting, 16 - 20 September Warsaw, Poland
1
The Henryk Niewodniczański Institute of Nuclear Physics Polish Academy of Science, Radzikowskiego 152 Street, 31-342 Cracow, Poland
2
AGH University of Science and Technology Faculty of Physics and Applied Computer Science Department of Solid State Physics, Adam Mickiewicz 30 Avenue, 30-059 Cracow, Poland
3
University College Dublin, School of Electrical and Electronic Engineering, Belfield 4, Dublin, Ireland
4
Warsaw University of Technology, Department of Physics, Koszykowa 75 Street, 00-062 Warsaw, Poland
Corresponding author: pawel.peczkowski@ifj.edu.pl , p.peczkowski@wp.pl
INTRODUCTION
The polycrystalline samples of YBa2Cu3O7-x High-Temperature Superconductor (HTS), also called „YBCO-123”, were prepared by mixing (II) oxide (CuO), carbonate (BaCO3) and yttrium (III) oxide (Y2O3)
powders and followed by a heat treatment high temperature (900 °C - 950 °C) flowing oxygen [1]. The polycrystalline samples of YBCO-Fe composites were prepared by grinding the mixture of single
phased YBCO-123 and small of iron (1% and 3% wt.), followed over by a heat treatment [2]. The results of structural (SEM, EDS, Raman spectroscopy), magnetic (AC susceptibility and magnetization
measurements) and magneto-transport on produced composites will be presented. Scanning electron microscopy (SEM) for YBCO and Fe mixtures showed iron particles homogeneously placed on YBCO
grains boundaries. As the concentration of iron particles increased the critical temperature decreased. The magnetization measurements LN temperature revealed transition from diamagnetic
to paramagnetic behaviour of YBCO-Fe samples originated from the iron grains.
SAMPELS PREPARATION (MILLING OF SUBSTRATES, FIRST CALCINATION, MILLING,
SECEND CALLCINATION, MILLING, FORMING OF SAMPLES, ANNEALING OXYGEN
ATMOSPHERE
MICROSTRUCTURE OBSERVATION (SEM) & PHASE ANALYSIS (XRD) FOR SAMPLE
Fig. 1. Curve of calcinatione in air atmosphere [1] Fig. 2. Curve of annealing in oxygen atmosphere [3]
RAMAN SPECTROSCOPY MAGNETIC PROPERTIES OF SAMPLES USING VIBRATING SAMPLE MAGNETOMETR (VSM)
Fig. 3. SEM image on the
break of the YBCO + 1% wt.
Fe sample.
Fig. 4. EDS map of the distri-
bution of elements in the
YBCO + 1% wt. Fe sample.
Fig. 5. EDS map of the distri-
bution of iron in the YBCO +
1% wt. Fe sample.
The iron is evenly distri-
buted throughout the
sample
RESULTS OF RESISTIVITY MEASUREMENTS
REFERENCES
[1] Pęczkowski P., Kowalik M., Zachariasz P., Jastrzębski C., Jaegermann Z., Szterner P., Woch W.M., Szczytko J., Synthesis and Phy-
sicochemical Properties of Nd-, Sm-, Eu-Based Cuprate High-Temperature Superconductors, Phys. Stat. Soli. A, 1700888(1-11),
2018, http://doi.org/10.1002/pssa.201700888.
[2] Pomorski K., Prokopow P., Perspective on architectures and properties of unconventional and field induced Josephson junction
devices, Inter. J. Microelec. Comp. Sci., 4(3), p. 110-115, 2013.
[3] Alagöz S. Production of YBCO superconductor sample by power-in-tube (PITM); and effect of Cd and Ga doping on the system,
Turk. J. Phys. 33, p. 69-80, 2009.
[4] Van der Pauw, L.J., A method of measuring the resistivity and hall Ccefficient on lamellae of arbitrary shape, Philips Tech. Rev. 20,
220-224, 1958.
ACKNOWLEDGMENTS
The authors would like to express their deepest gratitude to Dr. Dariusz Bocian (Institute of Nuclear Physics in Cracow), Dr. Andrzej Morawski (Institute of High Pressure Physics in Warsaw), Prof. Adam Witek (previous Director of Institute
of Ceramics and Building Materials in Warsaw) for helpful discussions, interest and valuable advices.
200 400 600 800
4.0x10
3
4.5x10
3
5.0x10
3
5.5x10
3
6.0x10
3
6.5x10
3
7.0x10
3
Ramanintensity[a.u.]
Raman shift [cm
-1
]
YBCO
YBCO-Fe:0.01
Fig. 6. Raman spectra of a pure YBCO
sample and YBCO sample with 1%
of Fe. Clearly visible raman peaks
characteristic for superconducting
phase. Superconducting properties of
YBCO samples are attributed to rich in
oxygen and well-defined orthorhombic
structures. For such orthorhombic struc-
ture the characteristic band is slightly
downshifted below 500cm-1
.
Fig. 7. Raman spectra of a pure YBCO
sample and YBCO sample with 3% of
Fe. The main raman peak is shifted to
higher values, above 500 cm-1
and
characterize the non superconducting
tetragonal crystal phase. Modes of
BaCuO2 phase or disorder modes
located above 600cm-1
are observed.
200 400 600 800
4.5x10
3
5.0x10
3
5.5x10
3
6.0x10
3
6.5x10
3
7.0x10
3
Ramanintensity[a.u.]
Raman shift [cm
-1
]
YBCO
YBCO-Fe:0.03
Fig. 8. Raman spectra of a pure YBCO
sample and YBCO sample with 7% of
Fe. The sample with 7% of Fe is non
homogenies and is composed with
a non superconducting phase with
precipitations of the superconducting
phase.
200 400 600 800
4.0x10
3
4.5x10
3
5.0x10
3
5.5x10
3
6.0x10
3
6.5x10
3
7.0x10
3
Ramanintensity[a.u.]
Raman shift [cm
-1
]
YBCO
YBCO-Fe:0.07
YBCO-Fe:0.07
Fig. 9. Magnetisation
against temperature in
magnetic field 15 mT for
YBCO + 0% wt. Fe
sample.
Fig. 10. Magnetisation
against temperature in
magnetic field 11.5 mT
for YBCO + 1% wt. Fe
sample.
Fig. 11. Hysteresis loop
of magnetization at 77 K
of YBCO + 0% wt. Fe
sample. Inset shows the
contribution from inter-
grain current.
Fig. 12. Hysteresis loop
of magnetization at 77 K
of YBCO + 1% wt. Fe
sample. Ferromagnetic
contribution of iron ox-
ide is visible. At small
μ0H no contribution to
magnetization of inter-
grain current is not
visible.
RESULTS OF MAGNETIC SUSCEPTIBILITY & CRITICAL CURRENT DENSITY MEASUREMENTS
Fig. 13. Dispersive (a) and absorption (b)
components of the AC susceptibility of the
pure YBCO sample.
Fig. 14. Dispersive (a) and absorption
(b) components of the AC susceptibility
of the YBCO + 1% wt. Fe sample.
Fig. 15. Critical current densities
(calculated from the absorption part of
AC susceptibility within the Bean critical
state model) of the pure YBCO sample.
The formula, which was used to fit the
data points and fit parameters are
shown in the table.
Sample Tc (K) jc(77K)
(Acm-2
)
YBCO+0% wt. Fe 91.3 120
YBCO+1% wt. Fe 87.6 less than 0.4
Fig. 16. Resistivity as a function of
temperature for pure YBCO and
YBCO + 1% wt. Fe samples. Arrows
indicate the critical temperature T c0.
Sample ρ(300K) / mΩcm
YBCO pure 1.25 ± 0.10
YBCO + 1%wt. Fe 3.70 ± 0.10
YBCO + 3%wt. Fe 30.5 ± 0.5
Resistivity at room temperature for pure
YBCO and YBCO + 1% wt. Fe samples
evaluated using the van der Pauw method [4].
Fig. 6. Qualitative and quanti-
tative phase analysis perfor-
med by X-ray diffraction (XRD)
for the YBCO + 1% wt. Fe
sample.