Interpocket polarization model for magnetic structures in rare-earth hexaborides
Abstract
The origin of peculiar magnetic structures in cubic rare-earth (R) hexaborides RB_6 is traced back to their characteristic band structure. The three sphere-like Fermi surfaces induce interpocket polarization of the conduction band as a part of a RKKY-type interaction. It is shown for the free-electron-like model that the interpocket polarization gives rise to a broad maximum in the intersite interaction I(q) around q=(1/4,1/4,1/2) in the Brillouin zone. This maximum is consistent with the superstructure observed in R=Ce, Gd and Dy. The wave-number dependence of I(q) is independently extracted from analysis of the spin-wave spectrum measured for NdB_6. It is found that I(q) obtained from fitting the data has a similarly to that derived by the interpocket polarization model, except that the absolute maximum now occurs at (0,0,1/2) in consistency with the A-type structure. The overall shape of I(q) gives a hint toward understanding an incommensurate structure in PrB_6 as well.
Cite
@article{arxiv.cond-mat/0207045,
title = {Interpocket polarization model for magnetic structures in rare-earth hexaborides},
author = {Yoshio Kuramoto and Katsunori Kubo},
journal= {arXiv preprint arXiv:cond-mat/0207045},
year = {2009}
}
Comments
5 pages, 3 figures, submitted to J.Phys.Soc.Jpn