Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "72.15.Qm" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 37
Tytuł:
Unusual Electron Transport Properties of $U_{0.05}Y_{0.95}Al_2$
Autorzy:
Tran, V.
Powiązania:
https://bibliotekanauki.pl/articles/1813710.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Jf
72.15.Qm
Opis:
We report a detailed study of the resistivity (ρ(T)) and thermoelectric power (S(T)) of the alloy $U_{0.05}Y_{0.95}Al_2$, which crystallises in the cubic $MgCu_2$-type structure. The resistivity is found to follow ρ(T) ∝ ln T between 15 and 40 K and a quasi-linear temperature dependence $-T^{1.16}$ for T <10 K. At a magnetic field of 9 T a Kondo-type maximum occurs in the resistivity data at 7 K, below which the Fermi liquid behaviour (ρ(T) ∝ $T^2$) is recovered. S(T)/T shows a $T^{0.5}$ power law for T <12 K. The low-temperature unconventional features observed in $U_{0.05}Y_{0.95}Al_2$ are presumably due to the presence of the two-channel Kondo effect.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 387-390
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Direct Coulomb Interactions on the Resistivity in NdPb$\text{}_{3}$
Autorzy:
Sławiński, P.
Kletowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1929856.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Eb
72.15.Qm
Opis:
In order to investigate the influence of the 4f electrons on the scattering processes we measured resistivity of the NdPb$\text{}_{3}$ in the temperature range 7-300 K. As a result, we could compare the experimentally determined magnetic contribution to the resistivity with the theoretically calculated ones for the exchange and quadrupolar scattering. The results may confirm that the direct Coulomb interactions between 4f and conduction electrons predominate.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 283-286
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Hydrogenation on the Electrical Resistivity of Amorphous Alloys
Autorzy:
Ornat, M.
Paja, A.
Powiązania:
https://bibliotekanauki.pl/articles/1377805.pdf
Data publikacji:
2014-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Cz
72.15.Qm
72.15.Rn
Opis:
Theoretical investigations of the influence of hydrogen contents on the electrical resistivity of amorphous metallic alloys have been carried out. We have made use of our method of calculations of the electrical resistivity of disordered systems based on the ground of Morgan-Howson-Saub and Evans models. Our method is fully quantum, includes multiple scattering effects and uses the scattering matrix operators for describing the electron-ion interactions. The model gives good agreement with experiment for many binary systems and should work for ternary systems as well, thus we performed calculations with hydrogen as one of the components of a ternary alloy. The results of our calculations show that the resistivity should increase with hydrogen concentration. Some experimental data confirm this predication.
Źródło:
Acta Physica Polonica A; 2014, 126, 6; 1296-1298
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Field Dependence of the Electrical Resistivity in Non-Fermi Liquid U$\text{}_{0.05}$Y$\text{}_{0.95}$Al$\text{}_{2}$, U$\text{}_{0.2}$Y$\text{}_{0.8}$Pd$\text{}_{3}$ and UCu$\text{}_{5-x}$Pd$\text{}_{x}$ (x=1.0,0.9)
Autorzy:
Strydom, A. M.
de V. Du Plessis, P.
Powiązania:
https://bibliotekanauki.pl/articles/2014439.pdf
Data publikacji:
2000-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Qm
71.27.+a
72.15.Gd
Opis:
We investigate the influence of applied magnetic fields up to B=8T on the electrical resistivity attemperatures down to 1.5K for three established non-Fermi liquid systems U$\text{}_{0.05}$Y$\text{}_{0.95}$Al$\text{}_{2}$, U$\text{}_{0.2}$Y$\text{}_{0.8}$Pd$\text{}_{3}$ and UCu$\text{}_{5-x}$Pd$\text{}_{x}$ (x=1.0,0.9). We follow the approach that an unconventional Kondo mechanism is often seen to be operative at low temperatures in some non-Fermi liquid systems where there are logarithmic or power-law divergences in the temperature dependences of magnetic susceptibility, the specific heat, and the electrical resistivity. In the above systems the incoherent Kondo scattering dominates the electrical resistivity ρ(T) at higher temperatures, while at low temperatures ρ~T$\text{}^{n}$ with n≈1, instead of n=2 as expected for a Fermi-liquid. We show how the power-law dependence is affected by a magnetic field. The isothermal magnetoresistivity as a function of field is analysed in terms of the Bethe ansatz description in order to extract values of the characteristic Kondo temperature T$\text{}_{K}$.
Źródło:
Acta Physica Polonica A; 2000, 98, 5; 593-597
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron Transport Properties of UAsSe
Autorzy:
Henkie, Z.
Fabrowski, R.
Wojakowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1929841.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.-v
72.15.Qm
75.50.Cc
Opis:
Anisotropy of resistivity (2-450 K), in-plane thermoelectric power (4-300 K) and Hall's constants (200-450 K) for UAsSe were determined. It is highly anisotropic, uniaxial ferromagnet below T$\text{}_{C}$ = 113 K. The compound is classified as Kondo lattice system becoming noncoherent below ≈ 0.5T$\text{}_{C}$.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 249-252
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seebeck Coefficient of CePd$\text{}_{3}$
Autorzy:
Mahan, G. D.
Bartkowiak, M.
Powiązania:
https://bibliotekanauki.pl/articles/2011215.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Jf
72.15.Qm
75.20.Hr
Opis:
Rare earth compounds have potential applications in thermoelectric devices due to their large value of conductivity and Seebeck coefficient. CePd$\text{}_{3}$ has the highest reported Seebeck coefficient (S ~ 125 μV/K), when doped appropriately, among all rare-earth compounds. This high value is explained as a result of the placement of the cerium f$\text{}^{1}$ level.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 37-42
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Polarized Transport through Quantum Dots: Coulomb Blockade and Kondo Effect
Autorzy:
Barnaś, J.
Świrkowicz, R.
Wilczyński, M.
Weymann, I.
Martinek, J.
Dugaev, V.
Powiązania:
https://bibliotekanauki.pl/articles/2036886.pdf
Data publikacji:
2003-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
73.23.Hk
72.15.Qm
Opis:
Spin related effects in electronic transport through quantum dots, coupled via tunneling barriers to two metallic leads, are discussed from the point of view of fundamental physics and possible applications in spin electronics. The effects follow either from long spin relaxation time in the dots or from spin dependent tunneling through the barriers when the external leads are ferromagnetic. In the former case large nonequilibrium spin fluctuations in the dot can be induced by flowing current. These fluctuations modify transport characteristics, particularly the shape of the Coulomb steps. In the latter case electric current depends on magnetic configuration of the system, and tunnel magnetoresistance effect due to magnetization rotation can occur. Transport properties in the weak coupling regime are described perturbatively in the first (sequential) and second (cotunneling) orders. In the strong coupling regime, on the other hand, the equation of motion for nonequilibrium Green functions is used to calculate electric current at low temperatures, where the Kondo peak in conductance is formed in the zero bias regime. In symmetrical systems the Kondo peak is split in the parallel magnetic configuration, whereas no splitting occurs for the antiparallel alignment. Theoretical results are discussed in view of available experimental data.
Źródło:
Acta Physica Polonica A; 2003, 104, 2; 165-177
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermoelectric Power and Thermal Conductivity of Heavy Fermion $CeCu_4Al$
Autorzy:
Falkowski, M.
Kowalczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/1426875.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.10.Fk
72.15.Eb
72.15.Jf
72.15.Qm
Opis:
The thermal conductivity and thermopower are discussed for the heavy fermion $CeCu_4Al$ compound. $CeCu_4Al$ is paramagnetic and follows the modified Curie-Weiss law with $μ_{eff}$ = 2.53 $μ_{B}$/f.u. and $\Theta_{P}$ = - 10 K indicating on the presence of well localized magnetic moments of $Ce^{3+}$ ions. The determined electronic specific heat coefficient γ = 2.2 J $mol^{-1}K^{-2}$ confirms the heavy fermion character of this compound. Thermopower is positive over the whole temperature range and below $T_{max}$ = 25 K falls rapidly. Based on a simple band model the position and width of the 4f peak nearest to the Fermi level have been estimated. The measured total thermal conductivity of the $CeCu_4Al$ compound increases almost linearly with increasing temperature.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1056-1058
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Magnetic Properties of URuGa
Autorzy:
Tran, V. H.
Troć, R.
Powiązania:
https://bibliotekanauki.pl/articles/1964580.pdf
Data publikacji:
1997-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Qm
75.40.Cx
75.80.+q
Opis:
We present data of the magnetic susceptibility χ(T) and electrical resistivity ρ(T) for the hexagonal URuGa (space group P6̅2m). Below 7 K, χ increases rapidly and the data can be described by the expression χ(T) = χ(0)(1-a√T). ρ(T) in zero field follows the activated form: ρ(T)∼ exp(E$\text{}_{a}$/2k$\text{}_{B}$T ) with E$\text{}_{a}$ = 1.9 meV. In an applied magnetic field of 1 T, the resistivity varies as ρ(T)∼ bT. Between 18 and 250 K the resistivity is linear in -lnT and consistent with a Kondo-like effect.
Źródło:
Acta Physica Polonica A; 1997, 92, 2; 299-302
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kondo Insulating State in CeRhSb$\text{}_{1-x}$Sn$\text{}_{x}$ as a Function of Carrier Number and Its Subsequent Metallization
Autorzy:
Ślebarski, A.
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/2047307.pdf
Data publikacji:
2007-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
72.15.Qm
71.30.+h
Opis:
A quantum critical point represents an essential singularity in the phase diagram of the electron-correlated compounds. In the CeRhSb$\text{}_{1-x}$Sn$\text{}_{x}$ system we have observed a quantum criticality at the boundary Kondo insulator-non-Fermi liquid state. In this series of compounds, CeRhSb has a Kondo insulating ground state, whereas CeRhSn exhibits a non-Landau Fermi liquid behavior. In view of different types of behavior of CeRhSb and CeRhSn, we review the results of the solution in CeRhSb$\text{}_{1-x}$Sn$\text{}_{x}$ and discuss the effect of a quasi-continuous change of the number of conduction electrons on the gap formation in the Kondo-insulating regime, as well as on the critical behavior appearance near the quantum critical point.
Źródło:
Acta Physica Polonica A; 2007, 111, 4; 487-496
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Do Van Hove Singularities in Leads Influence Tunneling Current through Quantum Dot?
Autorzy:
Krawiec, M.
Domański, T.
Wysokiński, K. I.
Powiązania:
https://bibliotekanauki.pl/articles/1991636.pdf
Data publikacji:
1998-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Gk
72.15.Qm
71.27.+a
Opis:
Using the Landauer type formula for the current through quantum dot we have studied the influence of the singularities in the density of states in leads on the differential conductance of the system and answered affirmatively the above question. The presence of Van Hove singularities in the leads may induce an additional structure on the conductance vs. voltage curve. The dot itself has been described by the single impurity Anderson model with a very strong "on-dot" Coulomb repulsion. We also simulate the effect of electron-phonon interaction in the dot by allowing for the fluctuations of the "impurity" energy level.
Źródło:
Acta Physica Polonica A; 1998, 94, 3; 411-414
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Magnetic Impurities in Gapless Fermi Systems
Autorzy:
Borkowski, L. S.
Powiązania:
https://bibliotekanauki.pl/articles/1955519.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Qm
75.20.Hr
74.70.Tx
Opis:
In ordinary metals, antiferromagnetic exchange between conduction electrons and a magnetic impurity leads to screening of the impurity spin below the Kondo temperature, T$\text{}_{K}$. In systems such as semimetals, small-gap semiconductors and unconventional superconductors, a reduction in available conduction states near the chemical potential can greatly depress T$\text{}_{K}$. The behavior of an Anderson impurity in a model with a power-law density of states, ρ(ε) ∝ |ε|$\text{}^{r}$, r>0, for |ε|<Δp, where Δp is small compared to the bandwidth, is studied using the non-crossing approximation. The transition from the Kondo singlet to the magnetic ground state can be seen in the behavior of the impurity magnetic susceptibility χ. The product Tχ saturates at a finite value at low temperature for coupling smaller than the critical one. For sufficiently large coupling Tχ → 0, as T → 0, indicating a complete screening of the impurity spin.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 359-362
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Transport and Thermal Properties of the Solid Solutions U$\text{}_{1-x}$Th$\text{}_{x}$Cu$\text{}_{5}$M (M = Al, Ga, In and Sn)
Autorzy:
Troć, R.
Tran, V. H.
Kaczorowski, D.
Czopnik, A.
Powiązania:
https://bibliotekanauki.pl/articles/2011211.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Mb
72.15.Qm
75.20.Hr
Opis:
UCu$\text{}_{5}$M-type compounds are moderate heavy fermion systems with an antiferromagnetic order below T$\text{}_{N}$ = 18, 16-25, and 25 K for M = Al, (Ga, In), and In, respectively, and a ferrimagnetic order with T$\text{}_{C}$ = 54 K for M = Sn. We present the results of magnetoresistance measurements as a function of temperature and applied magnetic field for the pure compounds and for their solid solutions containing Th, i.e. U$\text{}_{1-x}$Th$\text{}_{x}$Cu$\text{}_{5}$M. Only in the case of UCu$\text{}_{5}$In a substantial positive contribution to the magnetoresistance was observed at low temperatures, as for normal antiferromagnets. For the Al- and Sn-based alloys the magnetoresistance at low temperatures is negative, and its field variation proves the existence of Kondo-type interactions. On Th-substitution the magnetic phase transition is shifted to lower temperature and simultaneously the magnetoresistance becomes less negative. The field dependence of the magnetoresistance of these alloys can be well described by the Coqblin-Schrieffer model. Interestingly, the heat capacity measurements have revealed a general tendency to increase the linear coefficient γ with magnetic dilution of a given UCu$\text{}_{5}$M compound by Th-substitution. This feature reflects an enlargement of the effective mass of conduction electrons with the increase in both the unit cell volume and magnetic dilution. Such a tendency is also observed for the system UCu$\text{}_{5}$(In$\text{}_{1-x}$Ga$\text{}_{x}$), though the unit cell is here suppressed with increasing x. Thus, a similar physical picture is reached in all these systems but involving probably different mechanisms.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 25-35
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Substitution Study on the Coherent Kondo State in CeCu$\text{}_{5}$In
Autorzy:
Kaczorowski, D.
Kalychak, Ya. M.
Zaremba, V. I.
Powiązania:
https://bibliotekanauki.pl/articles/2012871.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Mb
72.15.Qm
75.20.Hr
Opis:
Ternary alloys CeCu$\text{}_{5-x}$In$\text{}_{1+x}$ were studied by means of magnetic and electrical resistivity measurements. In CeCu$\text{}_{5}$In a coherent Kondo state without long-range magnetic order develops at low temperatures. It transforms into an incoherent Kondo state upon small substitution of In for Cu.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 189-192
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral Functions of the Quantum Dot Coupled to Normal and/or Superconducting Leads
Autorzy:
Krawiec, M.
Wysokiński, K. I.
Powiązania:
https://bibliotekanauki.pl/articles/2012885.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Gk
72.15.Qm
71.27.+a
Opis:
We study the spectrum of the quantum dot coupled to two external leads, which may be normal and/or superconducting. The dot is described by the Anderson-Hubbard impurity model in the infinity U limit. The impurity spectral function shows complex behavior depending on the temperature and the state of the leads. For normal leads and at low temperature we observe the appearance of the Kondo resonance, while for BCS-like superconducting leads the bound states emerge due to absence of low energy excitations in the leads.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 197-200
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 37

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies