ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
As nonmagnetic yttrium is substituted for terbium, TbAg changes from a conventional antiferromagnet into a complex magnetic system with components of both commensurate and incommensurate spin structures and bulk magnetic properties typical of spin-glass behavior for x≤0.5. We have carried out neutron diffraction experiments on polycrystalline samples with x=0.15, 0.5, and 1.0 to complement our earlier studies for x=0.3.1 For x=0.5, the system orders at T≈58 K into the mixed structure observed for x=0.3, but with a much sharper (1/2 1/2 0) peak. On cooling below 40 K the incommensurate peaks almost disappear, remaining only as low-intensity shoulders of the commensurate peak at the lowest temperature measured (T=4 K). Hysteresis is observed in the relative intensity of the two components of the structure between 45 and 55 K. For x=0.15, the system orders at T≈18 K into the two-component structure, but with an approximately constant intensity ratio and no evidence of hysteresis, similar to the behavior found for x=0.3. Thus, as the Tb concentration decreases, the relative stability of the commensurate and incommensurate structures appears to change. This balance between competing magnetic structures will be related to the spin-glass properties observed in this system.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.344630
