Large moments in external fields of cubic group symmetry

Abstract

We predict that large moments $J$, placed into a crystal field with the cubic point symmetry group, differ by their spectrum and magnetic properties. E. g., properties of the odd-integer moments are different from those of the even-integer. The effect is due to Berry's phases gained by the moment, when it tunnels between minima of the external field. Two cases of the group $O$ are classified, namely, 6- and 8-fold coordinations. The spectrum and degeneration of energy levels depend on a remainder $\{J/n\}$, where the divisor $n=4$ and 3 for 6-fold and 8-fold coordination respectively. %High symmetry results in a finite magnetic moment for half-integer %and some integer moments, for example odd $J$ at 6-fold coordination. Large moments in the cubic environment can be realized by diluted alloys $R_{1-x}{R}_x^{\prime }$Sb, where R=Lu, La, and R${}^{\prime }$=Tb, Dy, Ho, Er.

4 pages, RevTeX, 4 figures, uses EPSF.sty