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FIZIKA A 10 (2001) 2 , 86-94
 
LETTER TO THE EDITOR
ENHANCEMENT OF FLUX PINNING IN NEUTRON IRRADIATED MgB2
SUPERCONDUCTOR
E. BABI�a, �. MILJANI�b, K. ZADROa,
I. KU�EV�a, �. MAROHNI�c,
�. DROBACc, X.L. WANGd and S.X. DOUd
aDepartment of Physics, University of Zagreb, Bijeni�ka 32,
HR-10000 Zagreb, Croatia,
bInstitute Ru�er Bo�kovi�, Bijeni�ka 54, HR-10002 Zagreb,
Croatia
cInstitute of Physics, Bijeni�ka 46, HR-10000 Zagreb,
Croatia
dCentre for Superconducting and Electronic Materials,
University of Wollongong, Wollongong, NSW 2522, Australia
Received 24 April 2001; revised manuscript received 8 October 2001
Accepted 15 October 2001
m-H loops for virgin and neutron irradiated bulk and powder
samples of MgB2 were measured in the temperature range 5-30
K in magnetic field B � 1 T. The irradiation at thermal
neutron fluences 9�1013 and 4.5�1014 cm-2
caused very small enhancement of m-H loops at lower
temperatures (T < 20 K), whereas the effect at high temperatures was unclear due to the
difficulty in achieving exactly the same measurement temperature prior and after
irradiation. However, the irradiation at 4.5�1015 cm-2
produced clear enhancement of m-H loops (hence Jc)
at all investigated temperatures, which provides the evidence for the enhancement of flux
pinning in MgB2 due to ion tracks resulting from n+10B reaction. The
potential of this technique for the enhancement of flux pinning in high temperature
superconductors is briefly discussed.
PACS numbers: 74.60.Ge,74.60.Jg,74.62.Dh,74.72.Hs
UDC 538.945
Keywords: virgin and neutron irradiated MgB2, bulk and powder samples,
field B � 1 T, temperature 5-30
K clear enhancement of m-H loops at 4.5�1015 cm-2, flux pinning
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