Metamagnetism

About: Metamagnetism is a research topic. Over the lifetime, 2023 publications have been published within this topic receiving 38108 citations.

Spin correlations in NaxCoO2 with x = 0.8 and 0.5

Abstract: We present magnetization, specific heat, and Hall coefficient measurements on high quality NaxCoO2 single crystals with x = 0.8 and 0.5. Similar to Na0.85CoO2, a metamagnetic transition at about 20 K with was observed in Na0.8CoO2 under a magnetic field of 9 T. This suggests that the common metamagnetic transition around 20 K would occur under a moderate magnetic field of ~9 T in NaxCoO2 with high x. For x = 0.5, we carried out elaborate specific heat investigations around 85 K under different magnetic fields. The results show an anisotropic nature of the transition at 85 K. This anisotropic property, revealed by both susceptibility and specific heat measurements, indicates that the spins are mainly pointing perpendicular to the c axis for x = 0.5 crystal. Moreover, by fitting the specific heat data below 46 K, a gap in low-lying excitation spectra is found and the gap value is estimated to be about 7.6 meV. This opening of the gap would account for the insulating ground state of Na0.5CoO2.

Low-temperature metamagnetic states in single crystal TbNi2B2C studied by torque magnetometry

Abstract: Metamagnetic transitions in single crystal TbNi2B2C have been studied at 19 K with a Quantum Design torque magnetometer The critical fields for the transitions depend strongly on the angle between the applied field and the easy axis [100] Torque measurements have been made while changing the angular direction of the magnetic field (parallel to basal tetragonal ab-planes) at fixed field magnitude and while changing the field magnitude at fixed angular direction over a wide angular range (more than two quadrants) Torque magnetometry (sensitive only to the component of magnetization perpendicular to the field) indicates not only a different sequence of metamagnetic phases for fields near the easy axis from those near the hard axis, but also the different natures of a principal metamagnetic phase near the hard axis Comparison of the results with longitudinal magnetization measurements is presented

Low-temperature transport properties of the intermetallic compound HoAgGe with a kagome spin-ice state

Abstract: We study the magnetic susceptibility, magnetization, resistivity and thermal conductivity of intermetallic HoAgGe single crystals at low temperatures and in magnetic fields along the $a$ and $c$ axis, while the electric and heat currents are along the $c$ axis. The magnetization curves show a series of metamagnetic transitions and small hysteresis at low field for $B \parallel a$, and a weak metamagnetic transition for $B \parallel c$, respectively. Both the magnetic susceptibility and $\rho(T)$ curve show anomalies at the antiferromagnetic transition ($T\rm_N \sim$ 11.3 K) and spin reorientation transition ($\sim$ 7 K). In zero field and at very low temperatures, the electrons are found to be the main heat carriers. For $B \parallel a$, the $\rho(B)$ curves display large and positive transverse magnetoresistance (MR) with extraordinary field dependence between $B^2$ and $B$-linear, accompanied with anomalies at the metamagnetic transitions and low-field hysteresis; meanwhile, the $\kappa(B)$ mainly decrease with increasing field and display some anomalies at the metamagnetic transitions. For $B \parallel c$, there is weak and negative longitudinal MR while the $\kappa(B)$ show rather strong field dependence, indicating the role of phonon heat transport.

Dynamical Mean-Field Study of Metamagnetism in Heavy Fermion Systems

Abstract: We investigate the metamagnetism in the periodic Anderson model with the k -dependent c – f mixing by using the dynamical mean-field theory combined with the exact diagonalization method. It is found that both effects of the k -dependent c – f mixing and strong correlation due to the Coulomb interaction between f electrons are significant for determining both the magnetization and the mass enhancement factor. For the case away from the half-filling, the results is consistent with the metamagnetic behavior observed in CeRu 2 Si 2 .