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Harrison N Sebastian SE Mielke CH Paris A Gordon MJ Swenson CA Rickel DG Pacheco MD Ruminer PF Schillig JB Sims JR Lacerda AH Suzuki MT Harima H Ebihara T 《Physical review letters》2007,99(5):056401
We report measurements of the de Haas-van Alphen effect in CeIn(3) in magnetic fields extending to approximately 90 T, well above the Néel critical field of mu(0)H(c) approximately 61 T. The unreconstructed Fermi surface a sheet is observed in the high magnetic field polarized paramagnetic limit, but with its effective mass and Fermi surface volume strongly reduced in size compared to that observed in the low magnetic field paramagnetic regime under pressure. The spheroidal topology of this sheet provides an ideal realization of the transformation from a "large Fermi surface" accommodating f electrons to a "small Fermi surface" when the f-electron moments become polarized. 相似文献
3.
CM Thaker S Rayaprol Krushna Mavani DS Rana MS Sahasrabudhe SI Patil DG Kuberkar 《Pramana》2002,58(5-6):1035-1039
The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO3 perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good
example of these properties is (La1−2x
Pr
x
Ca
x
)MnO3 (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T
c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using
X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for
understanding the structural, transport and magnetic properties are discussed in detail. 相似文献
4.
R.O. Nelson J.R. Williams D.R. Tilley D.G. Rickel N.R. Roberson S. Maripuu C.P. Cameron R.D. Ledford 《Nuclear Physics A》1976,261(3):427-438
The mean lifetimes of levels in 55Co below 5.2 MeV have been investigated with the Doppler-shift attenuation method and the 54Fe(3He, d)55Co reaction at 12 MeV. Scattered particles were detected in two E-ΔE telescopes at ±55° with respect to the beam axis, in coincidence with γ-rays observed at 90° and 130° in a 50 cm3 Ge(Li) detector. Mean lifetimes are reported for the following levels (energy in keV, lifetime in fs): 2166 (139±18), 2566 (680±200), 2923 (>245), 2939 (190±65), 3303 (99±22), 3323 (54±15), 3642 (680?300+400), 3943 (>170), 4164 (54±15), 4180 (<16), 4722 (<33), 4749 (<70) and 5174 (<40). The experimental results are compared with a detailed shell-model calculation. 相似文献
5.
§ 1.Introduction WearegivenkindependentWishartdensitiesofthe (p +q)× (p +q)randomsymmetricpositivedefinitematricesG1,… ,Gktobeg(Gi) =Kexp -12 trR- 1i Gi Gi12 (ni- q-p- 1) ,(1 )wherei=1 ,… ,k,andRidenotesthepopulationcorrelationmatrixofthei thpopulationandKasagenericletterdenote… 相似文献
6.
Fazio M.V. Freeman B.L. Hoeberling R.F. Kinross-Wright J. Rickel D.G. Stringfield R.M. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(3):305-311
Experiments at the microsecond pulse length have demonstrated that the virtual-cathode oscillator generates narrowband (0.3% bandwidth) microwave pulses when the virtual cathode is surrounded by a resonant cavity and is driven by an appropriate electron beam. This result is a significant departure from the behavior of a free-running virtual-cathode oscillator where the frequency depends on the (current density)1/2. The long-pulse experimental results are described 相似文献
7.
D.G. Rickel N.R. Roberson C.P. Cameron R.D. Ledford S.G. Buccino D.R. Tilley 《Nuclear Physics A》1976,256(1):152-162
Levels of 48V were populated by the 48Ti(p, nγ) and the 34S(16O, pnγ) reactions. Proton energies of 5.5, 6.0, 6.4 and 7.0 MeV and a 16O energy of 34 MeV were used. Gamma rays were measured in singles. The Jπ assignments for eight of these levels follows from γ-ray angular distribution and linear polarization measurements when combined with presently available lifetime and nucleon transfer data. 相似文献
8.
S Rayaprol Krushna Mavani CM Thaker DS Rana Keka Chakravorty SK Paranjape M Ramanadham Nilesh A Kulkarni DG Kuberkar 《Pramana》2002,58(5-6):877-880
A new series of mixed oxide superconductors with the stoichiometric composition La2−x
Dy
x
Ca
y
Ba2Cu4+y
O
z
(x=0.0 − 0.5, y=2x) has been studied for structural and superconductiong properties. Our earlier studies on La2−x
(Y/Er)
x
Ca
y
Ba2Cu4+y
O
z
series, show a strong dependence of T
c on hole concentration (p
sh). In the present work, the results of the analysis of the neutron diffraction measurements at room temprerature on x=0.3 and 0.5 samples are reported. It is interesting to know that Ca substitutes for both La and Ba site with concomitant
displacement of La onto Ba site. Superconductivity studies show that maximum T
c is obtained for x=0.5, y=1.0 sample (T
c ∼ 75 K), for La1.5Dy0.5Ca1Ba2Cu5O
z
(La-2125). 相似文献
9.
D.G. Rickel N.R. Roberson R.O. Nelson J.R. Williams D.R. Tilley 《Nuclear Physics A》1974,232(1):200-214
Levels of 50V were populated with the 50Ti(p, n)50V reaction at Ep = 4.50, 4.62 and 4.80 MeV. Gamma rays were measured in singles. From Doppler shift attenuation measurements mean lifetimes have been deduced for 9 levels below Ex = 2 MeV. The Jπ assignments for 8 of these levels follows from γ-ray angular distribution and linear polarization measurements. The transition strengths have been compared with calculations based on the wave functions of McCullen, Bayman and Zamick. 相似文献
10.
J.R. Williams C.R. Gould R.O. Nelson D.R. Tilley D.G. Rickel N.R. Roberson 《Nuclear Physics A》1975,253(2):365-379
Electromagnetic decay properties for seventeen states in 61Ni have been examined by means of the 58Fe(α,nγ)61Ni reaction with Eα = 8 MeV and the 60Ni(d, pγ)61Ni reaction at Ed = 6 MeV. Mean lifetimes were obtained with the Doppler-shift attenuation method. Spins, parities, and mixing ratios were determined from angular correlation studies and linear polarization measurements. The combined results permit new Jπ assignments of for the levels at 1016, 1611, 2020 and 2123 keV, respectively. Experimental results, including transition strengths, are compared to shell model predictions. 相似文献