Autor: Franco, V. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Scaling analysis of the magnetocaloric effect in Co/Au nanoparticles
Autorzy:: Hrubovčák, P.
Zeleňáková, A.
Zeleňák, V.
Franco, V.
Powiązania:: https://bibliotekanauki.pl/articles/1054838.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Sg
75.75.Fk
65.40.gd
Opis:: The system of superparamagnetic Co/Au bimetallic nanoparticles of average diameter 7 nm was investigated with respect to its magnetocaloric properties. DC magnetic measurements revealed the presence of field dependent zero field cooled M(T) maximum (6-8 K) and significant zero field cooled/field cooled irreversibility at low temperatures in the system. Documented thermal hysteresis disallow standard magnetic entropy change calculation from isothermal M(H) data, thus we attempted to employ zero field cooled M(T) data for this purpose. Magnetic entropy change was calculated employing the Maxwell relation. In maximal field variation of 1 T relative high magnetic entropy change for nanoparticles Δ S_M ≈ 0.7 J/(kg K) at T =9 K was observed. The data collapsed onto single universal curve after proper axis rescaling.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 795-797
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Magnetocaloric Effect in Nanostructured $Pr_2Fe_{17}$ and $Nd_2Fe_{17}$ Synthesized by High-Energy Ball-Milling
Autorzy:: Alvarez, P.
Sánchez-Marcos, J.
Sanchez Llamazares, J.
Franco, V.
Reiffers, M.
Blanco, J.
Gorria, P.
Powiązania:: https://bibliotekanauki.pl/articles/1534200.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.05.cp
75.50.Tt
75.30.Kz
Opis:: Nanocrystalline $Pr_2Fe_{17}$ and $Nd_2Fe_{17}$ powders with rhombohedral $Th_2Zn_{17}$-type crystal structure and average particle sizes around 20 nm have been obtained by high-energy ball milling. While the bulk alloys show a well-defined and sharp drop in the low-field magnetization curve at the Curie temperature, $T_{C}$ = 285 K (Pr) and 335 K (Nd), the ball-milled samples exhibit a substantial broadening of the ferro-to-paramagnetic transition due to a considerable augmentation of the disordered inter-grain boundaries. The latter results in an increase of more than 25% in the values of the full width at half maximum of the temperature dependence of the magnetic entropy change maintaining almost unchanged the relative cooling power.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 867-869
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Thermal Modelling of Quantum Cascade Lasers
Autorzy:: Spagnolo, V.
Vitiello, M.
Di Franco, C.
Scamarcio, G.
Powiązania:: https://bibliotekanauki.pl/articles/1791179.pdf
Data publikacji:: 2009-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.46.-w
61.82.Fk
68.35.Ct
Opis:: One of the top priorities in the development of quantum cascade laser sources is the optimization of the heat transport dynamic. We review here our experimental studies on the thermal properties of state of art quantum cascade lasers operating both in the mid-IR and THz ranges. The experimental approach is based on the investigation of the band-to-band photoluminescence signals, collected during device continuous wave operation. We measured the lattice temperature profile on the device front facet and using these data as inputs, we extract the heat dissipation patterns, the in-plane and the cross-plane active region thermal conductivities and the thermal boundary resistance for quantum cascade lasers based on different material systems.
Źródło:: Acta Physica Polonica A; 2009, 116, 4; 451-454
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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