Intrinsic coercive field in cubic intermetallic compounds. II: Tb xGd 1− xAl 2 and ErAl 2

Abstract

The thermal dependence of the coercive field in the pseudobinary cubic Laves phase compounds Tb x Gd 1− x Al 2(0 ⩽ x ⩽1.0) and ErAl 2 has been measured from 3.7 K up to de Cirie temperatures. The coercive field has two contributions: one from the intrinsic pinning of narrow domain walls in the Peierls crystal potential wells; this contribution is preponderant at low temperatures, decaying exponentially with the domain walls width. The other, which for x ⩾ 0.4 is dominant, comes out from the pinning of domain walls by defects (Kersten mechanism). The domain walls seem very narrow in those materials, between 2 and 5 interlayer atomic spacings.