We report measurements on single crystals of orthorhombic CeNiGe2, which is found to exhibit highly anisotropic magnetic and transport properties. The magnetization ratio M(H//b)/M(H^b) at 2 K is observed to be about 18 at 4 T and the electrical resistivity ratio r//b/r^b is about 70 at room temperature. It is confirmed that CeNiGe2 undergoes two-step antiferromagnetic transition at 4 and 3 K, as reported for polycrystalline samples. The application of magnetic field along the b axis (the easy magnetization axis) stabilizes a ferromagnetic correlation between the Ce ions and enhances the hopping of carriers. This results in large negative magnetoresistance along the b axis.
@article{arxiv.cond-mat/0201399,
title = {Magnetocrystalline Anisotropy in a Single Crystal of CeNiGe2},
author = {M. H. Jung and N. Harrison and A. H. Lacerda and P. G. Pagliuso and J. L. Sarrao and J. D. Thompson},
journal= {arXiv preprint arXiv:cond-mat/0201399},
year = {2009}
}