9
CHAPTER IV RESEARCH METHODOLOGY
The method of our research is experimental research described in the following figure
Figure 4. Diagram Block for research methodology Figure 2 shows the research methodology of our proposal. First part is samples
preparations. Polycrystalline samples of Eu
2-x
Ce
x
Cu
1-y
Zn
y
O
4
with y = 0, 0.005, 0.01, 0.02 and 0.05 were prepared by the ordinary solid-state reaction method as follows [15]. Raw
materials of Eu
2
O
3
, CeO
2
, CuO and ZnO powders were mixed in a stoichiometric ratio and prefired in air at 900
o
C for 20 h. The prefired materials are reground and pressed into pellets of 10 mm in diameter, and sintered in air at 1100
o
C for 16 h with repeated regrinding. As-grown samples of Eu
2-x
Ce
x
Cu
1-y
Zn
y
O
4
, are annealed in flowing Ar gas of high purity 6N at 950
o
C for 10 h in order to remove the excess oxygen at the apical site. All samples preparations will be doing in Unpad. Second part is checking quality and
measuring transport properties of the samples such as XRD, resistivity and DC magnetic- susceptibility measurements that carried out at low temperatures down to 2 K using a
standard SQUID magnetometer Quantum Design, Model MPMS-XL5 in a magnetic field of 10 Oe on field cooling. All the second part will be doing in Koike Laboratory at
Tohoku University. The third part is measuring spin dynamics properties by SR. The
ZF- and LF- SR measurements were performed at low temperatures down to 10 K at the
RIKEN-RAL Muon Facility at the Rutherford-Appleton Laboratory in the UK using a pulsed positive surface muon beam. This study will be useful for comparison with our
Electron- doped
system SC
Electron doping
Hole- doped
0.3
300 100
200
Hole
Quality checks
10 previous study in electron-doped Pr
1-x
LaCe
x
Cu
1-y
Zn
y
O
4
and hole-doped La
2-x
Sr
x
Cu
1- y
Zn
y
O
4
to find the key phenomena for explaining the appearance of high-T
c
superconductivity in the point of view spin dynamics properties.
11
CHAPTER V RESULTS
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