Critical scattering in the electrical resistance of GdB6 and DyB6

Autor: R. L. Singh, S. B. Woods
Rok vydání: 1981
Předmět:
Zdroj: Journal of Low Temperature Physics. 42:241-252
ISSN: 1573-7357
0022-2291
DOI: 10.1007/bf00120205
Popis: Detailed investigations of the electrical resistance of GdB6 and DyB6 near T N, their antiferromagnetic transition temperatures, and of nonmagnetic LaB6 are reported. In GdB6 a recently reported magnetic phase transition around 6 K has been found to be sample dependent. The resistance of this compound shows a very rapid increase at about T N = 15.15 K and a small maximum near 15.5 K. Analysis of the data using r = r0 + Bt + A±❘t❘1−α, where t = (T−T N )/T N , for −4 × 10−3 ⩽t⩽ −7 × 10−2, yields α ≈ 0.36. This is in agreement with a renormalization group theory prediction for a system with a three-dimensional lattice (d = 3) that is magnetically isotropic and has six spin degrees of freedom (n = 6). The resistance of DyB6 shows features of a typical antiferromagnetic transition with electron scattering mainly dominated by fluctuations in short-range spin correlations.Using the above expression for −1.8 × 10−2 ⩽t⩽ 4.8 × 10−2 with the A +term when t is positive and A −when t is negative, we obtain T N = 20.32 K and α = −0.16, which is close to the theoretical value (α = −0.17) for d = 3 and n = 4. The results are discussed in terms of the present theories for critical scattering.
Databáze: OpenAIRE
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