Autor: Kapusta, O. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Ordered Nanoporous Silica Modified with Nanoparticles of Lanthanide Oxides
Autorzy:: Zeleňáková, A.
Kapusta, O.
Zeleňák, V.
Powiązania:: https://bibliotekanauki.pl/articles/1368473.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.Fk
81.05.Rm
75.40.Cx
Opis:: Lanthanide oxide nanoparticles were encapsulated inside of pores of highly ordered periodic silica of SBA15 type with hexagonal symmetry. The magnetic properties of such nanoperticles were investigated. The structural characterization using the SAXS, XANES, XRD, and $N_{2}$ adsorption measurements showed the presence of lanthanide oxides of $Ln_{2}O_{3}$ type (Ln=La, Pr, Nd, Gd, Eu), with the size of about 5 nm, incorporated in nanoporous channel system. Their magnetic properties, studied by SQUID apparatus, showed the weak antiferromagnetic ordering at 2 K in the nanocomposites $Gd_{2}O_{3}$@SBA15, $Pr_{2}O_{3}$@SBA15 and $Nd_{2}O_{3}$@SBA15. This behaviour of the nanoparticles is caused by blocking process of magnetic moments, which at 300 K exhibit the superparamagnetism, evidenced from ZFC/FC magnetization.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 218-219
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Fe₂O₃ and Gd₂O₃ Nanoparticles Embedded in Mesoporous Silica: Magnetic Properties Comparison
Autorzy:: Kapusta, O.
Zeleňáková, A.
Hrubovčák, P.
Girman, V.
Zeleňák, V.
Powiązania:: https://bibliotekanauki.pl/articles/1031039.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 07.78.+s
47.11.Kb
75.75.Cd
75.40.Cx
78.20.-e
Opis:: Nanocomposite materials containing Fe₂O₃ and Gd₂O₃ nanoparticles with the same concentration were prepared by nanocasting method. At this procedure silica matrix serves as nanoreactor for growth of nanoparticles. Temperature and external dc field dependences of the magnetization both samples were compared. Composite containing Fe₂O₃ nanoparticles shows superparamagnetic behaviour with blocking temperature around 45 K. Otherwise, paramagnetic properties were observed for the sample with Gd₂O₃ (above 10 K). Additionally, due to free pores the silica matrix could serve as medium to increase the number of bonded water molecules. These properties together with appropriate magnetic characteristics make studied materials suitable for magnetic resonance imaging applications.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 860-862
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Magnetocaloric effect in Gd₂O₃@SiO₂ nanocomposite
Autorzy:: Zeleňáková, A.
Hrubovčák, P.
Berkutova, A.
Kapusta, O.
Zeleňák, V.
Powiązania:: https://bibliotekanauki.pl/articles/1054708.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Sg
81.05.Rm
75.20.Ck
75.75.Fk
Opis:: Nanocomposite consisting of Gd₂O₃ nanoparticles embedded in periodical porous silica matrix was investigated with respect to its magnetocaloric properties. Series of field (up to 5 T) dependence of magnetization data were recorded in temperature range 2-52 K. The data were subsequently processed employing Maxwell relation in order to calculate magnetic entropy change (Δ S_M) of the system. Examined nanocomposite exhibited reasonably high value of Δ S_M ≈ 29 J/(kg K) at maximal field change 5 T at the temperature of 2 K which suggests that this material could be feasible for cryomagnetic refrigeration applications.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 810-812
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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