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The development of magnetic behavior in the PrNi1-xCuxAl compounds
Fikáček, Jan
Title: The development of magnetic behavior in the PrNi1-xCuxAl compounds Author: Bc. Jan Fikáček Department: Department of Condensed Matter Physics Supervisor: Doc. Mgr. Pavel Javorský, Dr. Supervisor's e-mail address: javor@mag.mff.cuni.cz Abstract: In the present work we studied magnetic properties of the substituted PrNi1-xCuxAl series. A very interesting behavior had been reported in the previously studied systems with the same substitution, but with different rare earths contained, e.g. loss of long range order for certain concentrations of copper. We prepared polycrystalline samples of the PrNi1-xCuxAl (x = 0.1 - 0.9, 9 different stoichiometries) and measured them using X-ray diffraction, specific heat, magnetization and AC susceptibility. Additionally, powder neutron diffraction measurement on PrNi0.2Cu0.8Al sample was performed in ILL (Institut Laue Langevin) in Grenoble. Results of measurements on these compounds show on the presence of a long order in case of compounds with x = 0.1 - 0.4 below the ordering temperatures in the range of 3.4 - 5 K. Measurements of AC susceptibility and neutron diffraction revealed the loss of long range order in the rest of the series. In these compounds, the development of a spin glass state occurs below the temperatures between 3.4 and 4.5 K.
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The development of magnetic behavior in the PrNi1-xCuxAl compounds
Fikáček, Jan
Title: The development of magnetic behavior in the PrNi1-xCuxAl compounds Author: Bc. Jan Fikáček Department: Department of Condensed Matter Physics Supervisor: Doc. Mgr. Pavel Javorský, Dr. Supervisor's e-mail address: javor@mag.mff.cuni.cz Abstract: In the present work we studied magnetic properties of the substituted PrNi1-xCuxAl series. A very interesting behavior had been reported in the previously studied systems with the same substitution, but with different rare earths contained, e.g. loss of long range order for certain concentrations of copper. We prepared polycrystalline samples of the PrNi1-xCuxAl (x = 0.1 - 0.9, 9 different stoichiometries) and measured them using X-ray diffraction, specific heat, magnetization and AC susceptibility. Additionally, powder neutron diffraction measurement on PrNi0.2Cu0.8Al sample was performed in ILL (Institut Laue Langevin) in Grenoble. Results of measurements on these compounds show on the presence of a long order in case of compounds with x = 0.1 - 0.4 below the ordering temperatures in the range of 3.4 - 5 K. Measurements of AC susceptibility and neutron diffraction revealed the loss of long range order in the rest of the series. In these compounds, the development of a spin glass state occurs below the temperatures between 3.4 and 4.5 K.
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Kritický stav v tenkém Nb filmu
Youssef, A.E. ; Švindrych, Z. ; Hadač, J. ; Janů, Zdeněk
We present high resolution measurements of temperature dependence of low frequency ac magnetic susceptibility of superconducting Nb thin film in perpendicular time-varying periodic applied magnetic fields. We map this data, including harmonics, to the ac susceptibility calculated on basis of the complete analytical model of magnetization of thin superconducting disk in critical state. We find an excellent agreement between the measured and model data for temperatures up to 0.9997Tc
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