Quadrupolar and magnetic ordering in CeB6

The quadrupolar ordering in CeB6 is explained in terms of the electrostatic interaction of quadrupolar moments arranged into a simple cubic lattice. The representation of magnetic and quadrupolar moments by means of quasispins of two kinds is employed. A linear increase of the quadrupolar transition temperature TQ(H) with applied magnetic field and its further reentrance are described using a generalized spherical model which is well adjusted to a particular problem of the quadrupolar ordering in CeB6. The theory naturally explains the growing specific heat jump at TQ(H) with increasing magnetic field. The role of the quadrupolar ordering in the formation of the magnetic ordering, as well as the possible critical experiments and applications to other rare-earth compounds, are discussed. copyright 1997 The American Physical Society