Spin density wave Antiferromagnetism in FeGe2 and Fe_1-yCo_yGe_2
Abstract
An exploration of the magnetic and transport properties of the antiferromagnetic spin density wave compound FeGe2 with chemical substitution is in progress[1][2]. We have found that ligand substitution, Fe(Ge_1-xT_x)2 with T=Sb, Al, Ga, can be achieved up to x=0.1 for Sb and Al and to x=0.3 for Ga. The Neel temperature changes only slightly with these substitutions. In contrast, Fe_1-yCo_yGe2 remains single phase for y ≤ 0.58 and a reduction of the Neel Temperature from 290 K to 85 K is observed. The resistivity remains metallic while the residual resistivity rises to 150 μ ω cm. Hall effect measurements show an increase in the apparent carrier density with temperature in FeGe2 consistent with superzone gaps at the Fermi surface. Co doping increases the 300 K apparent carrier density, while at 10 K 0.1 carrier per Formula Unit is measured for all samples. The sensitivity of the magnetic ground state to pressure will be explored in an attempt to access a quantum critical point. [1] C P Adams, et al. J. Phys. Condens. Matter 9, 1347 (1997) [2] T E Mason, et al. Physica B 237-238, 449 (1997)
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARA20011G