The ground state of dilute Tm, Pr, and U systems is degenerate

✍ Scribed by M. Baliña; A.A. Aligia

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 304 KB
• Volume: 171
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(91)90500-e

✦ Synopsis

The ground state of the appropriate generalization of the impurity Anderson model for valence fluctuations between two realistic configurations, is obtained in the atomic, narrow-band limit, using the Lanczos method. This limit describes the strong-coupling fixed point of renormalization group treatments for intermediate valence and Kondo impurities. The resulting ground state of Tm is highly degenerate and contains states of total angular momentum 0, 1, 2, 2, 4 and 4. The ground state of Pr has J, = 9 and that of U has J, = 8. For Tm, the crystal electric field or and an applied magnetic field should split the degeneracy favouring the magnetic states. In agreement with experiments in Tm and U compounds the magnetic moment at the impurity is in all cases anomalously small. It decreases when L-S coupling is replaced by intermediate coupling and vanishes in the limit of j-j coupling.