arXiv subjects

K. Kosuge

Publications and source records attributed to K. Kosuge.

3 recordsLinked to original sources

arXiv2003

Spin Susceptibility and Superexchange Interaction in the Antiferromagnet CuO

Evidence for the quasi one-dimensional (1D) antiferromagnetism of CuO is presented in a framework of Heisenberg model. We have obtained an experimental absolute value of the paramagnetic spin susceptibility of CuO by subtracting the orbital susceptibility separately from the total susceptibility through the $^{63}$Cu NMR shift measurement, and compared directly with the theoretical predictions. The result is best described by a 1D $S=1/2$ antiferromagnetic Heisenberg (AFH) model, supporting the speculation invoked by earlier authors. We also present a semi-quantitative reason why CuO, seemingly of 3D structure, is unexpectedly a quasi 1D antiferromagnet.

cond-mat.str-el↗

arXiv2003

Deviation from the Kadowaki-Woods relation in Yb-based intermediate-valent systems

The T^2 coefficient of electrical resistivity, A, is compared with the electronic specific-heat coefficient, γ, for a number of Yb-based compounds. It is revealed that many systems including YbCuAl, YbInCu4, YbAl3 and YbCu5 show A/γ^2 values close to 0.4*10^{-6} μΩcm(mol K/mJ)^2, which is remarkably smaller than that known as the Kadowaki-Woods relation, A/γ^2 = 1.0*10^{-5} μΩcm(mol K/mJ)^2. Empirically, the compounds with the smaller A/γ^2 values appear to show weak intersite magnetic-correlation and/or to have almost fully-degenerated (J = 5/2 or 7/2) ground states.

cond-mat.str-el↗

arXiv2002

High-field magnetization of the 3d heavy-fermion system LiV$_2$O$_{4-d}$ (d = 0, 0.08)

Metamagnetic behavior has been observed in LiV2O4 powder sample around 38 T at 4.2 K. On the other hand, magnetization for oxygen deficient LiV2O3.92 shows no indication of metamagnetism up to 40 T, and shows substantially reduced magnetic moment compared to that of LiV2O4. These results suggest that ferromagnetic interaction is strongly enhanced by magnetic fields in LiV2O4, whereas antiferromagnetic interaction is dominant in LiV2O3.92.

cond-mat.str-el↗