ترغب بنشر مسار تعليمي؟ اضغط هنا

Nonlinear paramagnetic magnetization in the mixed state of CeCoIn_5

109   0   0.0 ( 0 )
 نشر من قبل Hong Xiao
 تاريخ النشر 2007
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Torque and magnetization measurements in magnetic fields $H$ up to 14 T were performed on CeCoIn$_5$ single crystals. The amplitude of the paramagnetic torque shows an $H^{2.3}$ dependence in the mixed state and an $H^{2}$ dependence in the normal state. In addition, the mixed-state magnetizations for both $Hparallel c$ and $Hparallel ab$ axes show anomalous behavior after the subtraction of the corresponding paramagnetic contributions as linear extrapolations of the normal-state magnetization. These experimental results point towards a nonlinear paramagnetic magnetization in the mixed state of CeCoIn$_5$, which is a result of the fact that both orbital and Pauli limiting effects dominate in the mixed state.

قيم البحث

اقرأ أيضاً

81 - H. Xiao , T. Hu , T. A. Sayles 2008
Magnetization and torque measurements were performed on CeCoIn$_5$ single crystals to study the mixed-state thermodynamics. These measurements allow the determination of both paramagnetic and vortex responses in the mixed-state magnetization. The par amagnetic magnetization is suppressed in the mixed state with the spin susceptibility increasing with increasing magnetic field. The dependence of spin susceptibility on magnetic field is due to the fact that heavy electrons contribute both to superconductivity and paramagnetism and a large Zeeman effect exists in this system. No anomaly in the vortex response was found within the investigated temperature and field range.
We study the effects of 10% Cr substitution in Mn sites of Bi0.5Sr0.5MnO3 on the antiferromagnetic (AFM) (TN ~ 110 K) transition using structural, magnetic and electron paramagnetic resonance (EPR) techniques. Field cooled (FC) and zero field cooled (ZFC) magnetization measurements done from 400 K down to 4 K show that the compound is in the paramagnetic (PM) phase till 50 K where it undergoes a transition to a short range ferromagnetic phase (FM). Electron paramagnetic resonance measurements performed in the temperature range 300 K till 80 K conform with the magnetization measurements as symmetric signals are observed owing to the paramagnetic phase. Below 80 K, signals become asymmetric. Electron paramagnetic resonance intensity peaks at ~ 110 K, the decreasing intensity below this temperature confirming the presence of antiferromagnetism. We conclude that below 50 K the magnetization and EPR results are consistent with a cluster glass phase of BSMCO, where ferromagnetic clusters coexist with an antiferromagnetic background.
Anomalous paramagnetic effects in dc magnetization were observed in the mixed state of LuNi2B2C, unlike any reported previously. It appears as a kink-like feature for H > 30 kOe and becomes more prominent with increasing field. A specific heat jump a t the corresponding temperature suggests that the anomaly is due to a true bulk transition. A magnetic flux transition from a square to an hexagonal lattice is consistent with the anomaly.
The magnetization field and temperature dependences in the paramagnetic phase of Mn1-xFexSi solid solutions with x<0.3 are investigated in the range B<5 T and T<60 K. It is found that field dependences of the magnetization M(B,T=const) exhibit scalin g behavior of the form Bpartial M/partial B-M=F(B/(T-Ts)), where Ts denotes an empirically determined temperature of the transition into the magnetic phase with fluctuation driven short-range magnetic order and F(c{hi}) is a universal scaling function for given composition. The scaling relation allowed concluding that the magnetization in the paramagnetic phase of Mn1-xFexSi is represented by the sum of two terms. The first term is saturated by the scaling variable c{hi}=B/(T-Ts), whereas the second is linearly dependent on the magnetic field. A simple analytical formula describing the magnetization is derived and applied to estimates of the parameters characterizing localized magnetic moments in the studied system. The obtained data may be qualitatively interpreted assuming magnetic inhomogeneity of the paramagnetic phase on the nanoscale.
Here we provide the first clear evidence of Fermi-liquid breakdown in an intermediate valence system. We employ high precision magnetization measurements of the valence fluctuating superconductor beta-YbAlB4 to probe the quantum critical free energy down to temperatures far below the characteristic energy scale of the valence fluctuations. The observed T/B scaling in the magnetization over three decades not only indicates unconventional quantum criticality, but places an upper bound on the critical magnetic field |B_c| < 0.2 mT, a value comparable with the Earths magnetic field and six orders of magnitude smaller than the valence fluctuation scale. This tiny value of the upper bound on B_c, well inside the superconducting dome, raises the fascinating possibility that valence fluctuating beta-YbAlB4 is intrinsically quantum critical, without tuning the magnetic field, pressure, or composition: the first known example of such a phenomenon in a metal.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا