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Abstracts
P1.18
Theoretical and experimental study of properties of HoFe
6
Al
6
-H
single
crystals with a magnetic compensation point at temperatures near
absolute zero
I.S. Tereshina(1), A.K. Zvezdin(2,3), A.V. Andreev(4), J. ˇSebek(4), M.D.
Davidova(3), D.I. Gorbunov(5), E.A. Tereshina(4), Ch. Sabdenov(3), Y.
Skourski(5)
1) Lomonosov Moscow State University, Faculty of Physics, 119991 Moscow,
Russia
2) A. M. Prokhorov General Physics Institute of Russian Academy of Sciences,
119991 Moscow, Russia
3) Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
4) Institute of Physics, Czech Academy of Sciences, 182 21 Prague, Czech
Republic
5) Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum
Dresden-Rossendorf, D-01314 Dresden, Germany
Ferrimagnetic HoFe
6
Al
6
(tetragonal ThMn
12
-type crystal structure) has a
compensation point for the Ho and Fe magnetic sublattices at temperatures
near absolute zero. The influence of hydrogen addition on the magnetism of a
HoFe
6
Al
6
is studied. Hydrogenation increases the Fe sublattice magnetic moment
from 10 to 10.45
µ
B as a result of volume expansion and thus, decompensates
Fe and Ho sublattices. H-T phase diagrams and a full magnetization process of
the HoFe
6
Al
6
Hx (x = 0; 1) single crystals are obtained theoretically by using a
single-ion model for the crystal-electric-field interaction and a mean-field model
for exchange interaction. Experimental study is carried out in fields up to 60 T.
P1.19
Comparison of Critical Current Scaling Behaviors in MgB2/SiC/Si
thin films
Akihiko Nishida(1), Chihiro Taka(1), Stefan Chromik(2), Rudolf Durny(3)
1) Department of Applied Physics, Fukuoka University, 8-19-1 Nanakuma,
Jonan-ku Fukuoka 814-0180, Japan
2) Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska
cesta 9, 841 04 Bratislava, Slovak Republic
3) Department of Physics, Slovak University of Technology, Ilkovicova 3, 812 19
Bratislava, Slovak Republic
Scaling behaviors of critical current density Jc in MgB2 thin films are
investigated on different films with thickness of 100nm, 50nm and 10nm based
on comprehensive scaling formula. Experimental data are reduced and analyzed
with the formula over a wide range of magnitudes. In 100nm and 50nm films
single scaling function has been able to fit experimental Jc data oven ten orders
of magnitudes with appropriate flux pinning parameters. On the other hand, for
the 10nm film, we find different Jc dependences on temperature and magnetic
field, suggesting anomalous or low dimensional superconductivity.
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