Magnetic ordering in uranium compounds with AuCu3-type lattice

Abstract

The magnetic structures of UIn3 and UTl3 at 4.2° K has been determined by neutron diffraction using powder samples. In both compounds the magnetic unit cell is formed by doubling the chemical cell in three directions. The magnetic moment alignment of uranium ions is in opposite direction in the adjacent (111) planes. μ was found to be 1.60 BM in UTl3 and about 1 BM in UIn3. The Néel temperature of UTl3 was determined to be (90 ± 5)° K. The stability of magnetic structures of UTl3 and UIn3, as well as UPb3 has been discussed in terms of molecular field theory.