Wszystkie pola: Karpiński, J. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Interplay Between Spin Density Wave and Superconductivity in `122 Iron Pnictides: $\text{}^{57}Fe$ Mössbauer Study
Autorzy:: Błachowski, A.
Ruebenbauer, K.
Żukrowski, J.
Bukowski, Z.
Matusiak, M.
Karpinski, J.
Powiązania:: https://bibliotekanauki.pl/articles/1431157.pdf
Data publikacji:: 2012-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.70.Xa
75.30.Fv
76.80.+y
Opis:: Iron-based superconductors $Ba_{0.7}Rb_{0.3}Fe_{2}As_{2}$ and $CaFe_{1.92}Co_{0.08}As_{2}$ of the `122' family have been investigated by means of the 14.41-keV Mössbauer transition in $\text{}^{57}Fe$ versus temperature ranging from the room temperature till 4.2 K. A comparison is made with the previously investigated parent compounds $BaFe_{2}As_{2}$ and $CaFe_{2}As_{2}$. It has been found that Mössbauer spectra of these superconductors are composed of the magnetically split component due to development of spin density wave and non-magnetic component surviving even at lowest temperatures. The latter component is responsible for superconductivity. Hence, the superconductivity occurs in the part of the sample despite the sample is single phase. This phenomenon is caused by the slight variation of the dopant concentration across the sample (crystal).
Źródło:: Acta Physica Polonica A; 2012, 121, 4; 726-729
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Thermoelectric Power of $MgB_2$ Single Crystals Doped with Holes and Electrons
Autorzy:: Oganisian, K.
Rogacki, K.
Sulkowski, C.
Zhigadlo, N.
Katrych, S.
Karpinski, J.
Powiązania:: https://bibliotekanauki.pl/articles/1812320.pdf
Data publikacji:: 2008-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.25.Fy
74.70.Ad
74.62.Dh
Opis:: The thermoelectric power of $MgB_2$ single crystals, non-substituted, single-substituted with C, and co-substituted with C and Li, was investigated in the temperature range from 10 to 300 K. Both the in-plane $(S_ab)$ and the out-of-plane $(S_c)$ thermoelectric powers are positive for non-substituted crystals and both $S_{ab}$ and $S_c$ change a sign for crystals doped with electrons when C is substituted for B in the amount larger than 6 at.%. The substitution of C, which supplies electrons mainly into the σ band, reduces the thermoelectric power anisotropy, most likely by increasing the interband scattering. When Li is additionally co-substituted for Mg, $S_ab$ remains unchanged but $S_c$ increases substantially. The Li substitution donates holes into the π band rather than into the σ band and in this way modifies the π band properties, including the possible increase in the intraband scattering.
Źródło:: Acta Physica Polonica A; 2008, 114, 1; 191-195
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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