T. O. Brun

Field-Induced Transitions in DySb,

The NaCl‐structured compound DySb, which in zero field transforms abruptly at TN?9.5 K to a Type‐II antiferromagnetic (A) state with a nearly tetragonal lattice distortion, was previously found to exhibit rapid field‐induced changes in magnetization at 1.5 K. The field‐induced transitions in a DySb crystal have been studied by neutron diffraction and magnetization measurements in fields up to ∠60 kOe applied parallel to each of the principal axes. In the 〈100〉 case, the transition from the A toan intermediate ferrimagnetic (Q) state is first‐order at 4.2 K (critical field Hc?21 kOe) but is continuous from ∠6 K up to TN, as Hc→O. The Q‐to‐paramagnetic (P) transition is rapid but continuous at 4.2 K (Hc?40 kOe) and becomes broad as TN is approached. In the 〈110〉 case the A‐to‐Q transition remains essentially first‐order from 4.2 K (Hc?15 kOe) up to TN; above TN rapid P‐to‐Q transitions occur at very high fields. The magnetic structure of the Q state is found to be that of HoP.

Disorder and transport in lithium/aluminum

Abstract Neutron powder diffraction measurements on β-LiAl have proven that the defects formed at high temperature are reciprocal pairs of antisite defects, Li Al and Al Li . These reciprocal pairs are generated over the entire β-phase domain. The formation of the antisites is not due to an order-disorder transformation. The relation between the antisite defects and Li diffusion cannot be established directly from the present experiments.