Critical scattering in the electrical resistance of GdB6and DyB6

✍ Scribed by R. L. Singh; S. B. Woods

• Publisher: Springer US
• Year: 1981
• Tongue: English
• Weight: 536 KB
• Volume: 42
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00120205

✦ Synopsis

Detailed investigations of the electrical resistance of GdB6 and DyB6 near TN, 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 TN = 15.15 K and a small maximum near 15.5K. Analysis of the data using r=ro+Bt+A•

x-~, where t= (T-TN)/T/v, for -4 x 10 -3 <~t <_ -7x 10 -2, yields a ~-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• <-t<-4.8• -2 with the A+ term when t is positive and A_ when t is negative, we obtain TN = 20.32 K and a = -0.16, which is close to the theoretical value (a =-0.17) for d=3 and n=4. The results are discussed in terms of the present theor&s for critical scattering.