Electrical resistance at the antiferro-paramagnetic transition in dysprosium

Abstract

High precision data for the electrical resistance of dysprosium in the region of the Neel point have been obtained using the direct current comparator method. Results are given for both b- and c-axis samples cut from the same high quality monocrystal. In the immediate vicinity of the Neel point (BT-TN mod <or=2.5K), the c-axis resistance, Rc, cannot be convincingly described by a power law. Reasons for this are discussed. However, Rc is described by a power law for 2.5<or=T-TN<or=60K and for -15<or approximately=T-TN<or approximately=-2.5K with exponents psi +=0.60 and psi - approximately=1.25 respectively. In the case of b-axis data, Rb is linearly dependent on T for T>or=TN, whereas a power law, of weak amplitude but with psi - approximately=1.25, is valid below TN. The results suggest that dR/dT varies as the magnetic specific heat below TN for both the b- and c-axis resistance.